Package {geocausal}

Type:	Package
Title:	Causal Inference with Spatio-Temporal Data
Version:	0.4.2
Maintainer:	Mitsuru Mukaigawara <mitsuru_mukaigawara@g.harvard.edu>
Description:	Spatio-temporal causal inference based on point process data. You provide the raw data of locations and timings of treatment and outcome events, specify counterfactual scenarios, and the package estimates causal effects over specified spatial and temporal windows. See Papadogeorgou, et al. (2022) <doi:10.1111/rssb.12548> and Mukaigawara, et al. (2024) <doi:10.31219/osf.io/5kc6f>.
License:	MIT + file LICENSE
URL:	https://github.com/mmukaigawara/geocausal
Encoding:	UTF-8
LazyData:	true
Suggests:	elevatr, gridExtra, knitr, readr, gridGraphics
Imports:	crsuggest, ggthemes, data.table, dplyr, furrr, ggplot2, ggpubr, mclust, progressr, purrr, Rglpk, sf, spatstat.explore, spatstat.geom, spatstat.model, spatstat.univar, spatstat.random, terra, tibble, tidyr, tidyselect, tidyterra
Depends:	R (≥ 3.5.0)
Config/roxygen2/version:	8.0.0
NeedsCompilation:	no
Packaged:	2026-06-26 09:36:01 UTC; mitsurumukaigawara
Author:	Mitsuru Mukaigawara [cre, aut], Lingxiao Zhou [aut], Georgia Papadogeorgou [aut], Jason Lyall [aut], Kosuke Imai [aut]
Repository:	CRAN
Date/Publication:	2026-06-26 09:50:02 UTC

geocausal: Causal Inference with Spatio-Temporal Data

Description

The geocausal package implements causal inference analytic methods based on spatio-temporal data. Users provide the raw data of locations and timings of treatment and outcome events, specify counterfactual scenarios, and the package estimates causal effects over specified spatial and temporal windows.

Details

A typical workflow proceeds as follows:

1. **Prepare spatial objects**: define the analysis window with [get_window()] and, if needed, covariate surfaces such as distances from foci ([get_dist_focus()]), distances from lines ([get_dist_line()]), and elevation ([get_elev()]). 2. **Prepare the data**: convert the raw event data into a hyperframe of point patterns with [get_hfr()], smooth the outcomes with [smooth_ppp()] or count them by pixel with [pixel_count_ppp()]. 3. **Estimate densities**: model the observed treatment intensity with [get_obs_dens()] (the propensity score), and construct counterfactual densities from a baseline density ([get_base_dens()]) and, optionally, power densities ([get_power_dens()]) using [get_cf_dens()]. 4. **Estimate causal effects**: compare counterfactual scenarios with [get_est()] for average treatment effects, [get_cate()] for heterogeneous effects, and [get_sens()] and [get_cate_sens()] for sensitivity analyses. 5. **Check the model**: assess model validity with out-of-sample prediction ([dx_outpred()]) and superthinning tests ([dx_supthin()]).

The package ships with example data from the Iraq war ('insurgencies', 'airstrikes', their 2006 subsets, and 'iraq_window').

Author(s)

Maintainer: Mitsuru Mukaigawara mitsuru_mukaigawara@g.harvard.edu (ORCID)

Authors:

• Mitsuru Mukaigawara mitsuru_mukaigawara@g.harvard.edu (ORCID)

• Lingxiao Zhou zhou.l@ufl.edu

• Georgia Papadogeorgou gpapadogeorgou@ufl.edu (ORCID)

• Jason Lyall Jason.Lyall@dartmouth.edu (ORCID)

• Kosuke Imai imai@harvard.edu (ORCID)

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

Mukaigawara, M., Zhou, L., Papadogeorgou, G., Lyall, J. and Imai, K. (2024). geocausal: An R package for spatio-temporal causal inference. OSF preprint. doi:10.31219/osf.io/5kc6f

See Also

Useful links:

• https://github.com/mmukaigawara/geocausal

airstrikes

Description

A dataset of airstrikes in Iraq (February to June 2007)

Usage

airstrikes

Format

A tibble with 3938 rows and 4 variables:

date

Date (YYYY-MM-DD)

longitude

Longitudes (decimal)

latitude

Latitudees (decimal)

type

Types of airstrikes (airstrikes or shows of force (SOF))

Examples

airstrikes

airstrikes_2006

Description

A dataset of airstrikes in Iraq in 2006 (2006/1/1-2006/9/24)

Usage

airstrikes_2006

Format

A tibble with 2101 rows and 4 variables:

date

Date (YYYY-MM-DD)

longitude

Longitudes (decimal)

latitude

Latitudees (decimal)

type

Types of airstrikes (airstrikes or shows of force (SOF))

Examples

airstrikes_2006

Convert windows into sf objects

Description

'conv_owin_into_sf' takes an owin object and converts it to sf-related objects. This function is mostly an internal function of other functions.

Usage

conv_owin_into_sf(window)

Arguments

Details

'conv_owin_into_sf()' converts the window to a polygonal object, extracts its boundary coordinates (closing the ring if necessary), and returns the same boundary in several representations: an 'sf' 'POLYGON', a coordinate data frame, an 'sfc_POLYGON', an 'sf' object, and a 'SpatialPolygonsDataFrame'. It is mostly used internally by other functions that need different spatial object classes.

Value

list of polygon, dataframe, sfc_POLYGON, sf, and SpatialPolygonsDataFrame objects

See Also

Other spatial utility functions: get_dist_focus(), get_dist_line(), get_distexp(), get_elev(), get_window()

Perform out-of-sample prediction

Description

'dx_outpred()' performs out-of-sample prediction (separating data into training and test sets). It assumes that training and test sets have the same window.

Usage

dx_outpred(
  hfr,
  ratio,
  dep_var,
  indep_var,
  ndim = 128,
  resolution = NULL,
  window
)

Arguments

Details

'dx_outpred()' splits the hyperframe chronologically into a training set (the first 'ratio' fraction of rows) and an implied test set, fits a Poisson point process model to the training data with 'spatstat.model::mppm()', and predicts the conditional intensity over the full hyperframe. It returns the predicted intensity images together with the integrated (estimated) event counts and the per-period sums of log intensities, which can be compared against observed counts to assess out-of-sample fit. Training and test sets are assumed to share the same window.

Value

list of the following: * 'indep_var': independent variables * 'coef': coefficients * 'intens_grid_cells': im object of observed densities for each time period * 'estimated_counts': the number of events that is estimated by the poisson point process model for each time period * 'sum_log_intens': the sum of log intensities for each time period * 'training_row_max': the max row ID of the training set

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

[get_obs_dens()]

Other diagnostic functions: dx_supthin()

Examples

# Prepare data: airstrikes (treatment) in Iraq, 2006 (first 60 days)
dat <- airstrikes_2006[airstrikes_2006$type == "Airstrike", ]
dat$type <- "airstrike"
dat$time <- as.numeric(dat$date - min(dat$date) + 1)
dat <- dat[dat$time <= 60, ]
hfr <- get_hfr(data = dat, col = "type", window = iraq_window,
               time_col = "time", time_range = c(1, 60),
               coordinates = c("longitude", "latitude"), combine = FALSE)
hfr$dist_bag <- rep(list(get_dist_focus(window = iraq_window, lon = 44.366,
                                        lat = 33.315, ndim = 64)), nrow(hfr))

# Out-of-sample prediction with an 80/20 split
pred <- dx_outpred(hfr, ratio = 0.8, dep_var = "airstrike",
                   indep_var = "dist_bag", ndim = 64, window = iraq_window)

Perform superthinning tests

Description

'dx_supthin()' performs superthinning tests to examine model validity.

Usage

dx_supthin(
  hfr,
  dep_var,
  indep_var,
  window,
  rescale = 1,
  max_r = 50,
  n_sample = 1000,
  nsim = 1000,
  unit = "km"
)

Arguments

Details

'dx_supthin()' assesses model validity through superthinning. It fits a Poisson point process model with 'spatstat.model::mppm()', then for each time period thins the observed points and superposes simulated points so that, under a correctly specified model, the combined pattern is approximately homogeneous Poisson at the constant rate 'cval'. Global envelope tests on the L- and K-functions ('spatstat.explore::envelope()') are computed on the pooled, optionally subsampled ('n_sample'), pattern using 'nsim' simulations out to 'max_r'. The returned 'supthin' data frame stacks the L- and K-function envelopes for plotting.

Value

A list of resulting dataframe ('result_data'), windows ('window_list'), data for distance quantiles, and a window object for the entire window

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

[get_obs_dens()]

Other diagnostic functions: dx_outpred()

Examples

# Prepare data: airstrikes (treatment) in Iraq, 2006 (first 60 days)
dat <- airstrikes_2006[airstrikes_2006$type == "Airstrike", ]
dat$type <- "airstrike"
dat$time <- as.numeric(dat$date - min(dat$date) + 1)
dat <- dat[dat$time <= 60, ]
hfr <- get_hfr(data = dat, col = "type", window = iraq_window,
               time_col = "time", time_range = c(1, 60),
               coordinates = c("longitude", "latitude"), combine = FALSE)
hfr$dist_bag <- rep(list(get_dist_focus(window = iraq_window, lon = 44.366,
                                        lat = 33.315, ndim = 64)), nrow(hfr))

# Superthinning test (use a larger nsim in real applications)
supthin <- dx_supthin(hfr, dep_var = "airstrike", indep_var = "dist_bag",
                      window = iraq_window, nsim = 19)

Generate adaptive intervention densities based on historical data

Description

'get_adaptive_baseline_dens()' takes a hyperframe for historical data and returns fitted densities for the current data. The output is used as counterfactural densities.

Usage

get_adaptive_baseline_dens(
  hfr_hist,
  hfr_current,
  dep_var,
  indep_var,
  ngrid = 100,
  window
)

Arguments

Details

'get_adaptive_baseline_dens()' assumes the poisson point process model and calculates observed densities for each time period. It depends on 'spatstat.model::mppm()'. Users should note that the coefficients in the output are not directly interpretable, since they are the coefficients inside the exponential of the poisson model.

Value

list of the following: * 'indep_var': independent variables * 'coef': coefficients * 'intens_grid_cells': im object of observed densities for each time period * 'estimated_counts': the number of events that is estimated by the poisson point process model for each time period * 'sum_log_intens': the sum of log intensities for each time period * 'actual_counts': the number of events (actual counts)

See Also

Other density estimation functions: get_base_dens(), get_cf_dens(), get_cf_dens_adaptive(), get_cf_sum_log_intens(), get_obs_dens(), get_power_dens(), sim_cf_dens(), sim_power_dens()

Get the baseline density

Description

'get_base_dens()' takes a dataframe and returns the baseline densities using Scott's rule of thumb (out-of-sample data).

Usage

get_base_dens(
  window,
  ndim = 128,
  resolution = NULL,
  out_data = NULL,
  out_coordinates = c("longitude", "latitude"),
  input_crs = 4326,
  unit_scale = 1000
)

Arguments

Details

'get_base_dens()' estimates a baseline (out-of-sample) density from point data supplied in 'out_data'. The points are projected to match the CRS attached to 'window', converted to a 'ppp' object, and smoothed by a kernel density estimate whose bandwidth is chosen by Scott's rule of thumb ('spatstat.explore::bw.scott()'). The result is normalized to integrate to one. The output grid is controlled either by 'ndim' or, if supplied, by 'resolution' (in km per pixel), which overrides 'ndim'. The window must carry a CRS attribute (e.g., created via 'get_window()' with a 'target_crs').

Value

an im object of baseline density

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

[get_cf_dens()]

Other density estimation functions: get_adaptive_baseline_dens(), get_cf_dens(), get_cf_dens_adaptive(), get_cf_sum_log_intens(), get_obs_dens(), get_power_dens(), sim_cf_dens(), sim_power_dens()

Examples

# Baseline density from out-of-sample (2007--2008) insurgency data
base <- get_base_dens(window = iraq_window, ndim = 64,
                      out_data = insurgencies,
                      out_coordinates = c("longitude", "latitude"))

Generate a Hajek estimator for heterogeneity analysis

Description

A function that returns a Hajek estimator of CATE for a spatial or spatio-temporal effect modifier

Usage

get_cate(
  obs,
  cf1,
  cf2,
  treat,
  pixel_count_out,
  lag,
  trunc_level = 0.95,
  time_after = TRUE,
  entire_window = NULL,
  em = NULL,
  E_mat = NULL,
  nbase = 6,
  spline_type = "ns",
  intercept = TRUE,
  eval_values = NULL,
  eval_mat = NULL,
  test_beta = NULL,
  save_weights = TRUE,
  ...
)

Arguments

Details

'E_mat' should be a matrix or array of dimensions n by m where n is the product of image dimensions and number of time period, and m is 'nbase'-'intercept'. If you want to construct your own covariate matrix 'E_mat', you should use 'get_em_vec()' to convert the effect modifer(usually a column of a hyperframe) to a vector, and then construct the splines basis based on the vector. The covariate matrix'E_mat' should not the column for intercept. The function 'get_cate()' will conduct a hypothesis testing on whether all the selected coefficients are 0. 'test_beta' is a vector of positive integers specifying the indices of the chosen beta. The coefficients (except the intercept) are indexed by '1,2,...,nbase-intercept'. By default, it test whether all the coefficients(except the intercept) are 0, and this is testing the the heterogeneity effect of the effect modifier.

Value

list of the following: 'est_beta': estimated regression coefficient 'V_beta': estimated asymptotic covariance matrix of regression coefficient (normalized by total time periods) 'chisq_stat': observed chi-square statistics for the hypothesis test 'p.value': observed chi-square statistics for the hypothesis test 'specification': information about the specification of the spline basis and the values on which the CATE is estimated 'est_eval': estimated CATE evaluted at chosen values 'V_eval': estimated asymptotic covariance matrix of the estimated CATE values (normalized by total time periods) 'mean_effect': Mean of the pseudo pixel effect 'total_effect': Mean of the pseudo effect for the window 'entire_window'. It is equal to mean effect times the total number of pixels inside the chosen window

References

Zhou, L., Imai, K., Lyall, J. and Papadogeorgou, G. (2024). Estimating heterogeneous treatment effects for spatio-temporal causal inference: how economic assistance moderates the effects of airstrikes on insurgent violence. arXiv preprint. doi:10.48550/arXiv.2412.15128

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

[get_cate_sens()], [get_em_vec()], [pixel_count_ppp()]

Other causal effect estimation functions: get_est(), get_estimates(), get_var_bound(), get_weighted_surf()

Examples

# Prepare data: airstrikes (treatment) and insurgencies (outcome), Iraq 2006
dat <- rbind(airstrikes_2006[airstrikes_2006$type == "Airstrike", ],
             insurgencies_2006)
dat$type <- ifelse(dat$type == "Airstrike", "airstrike", "insurgency")
dat$time <- as.numeric(dat$date - min(dat$date) + 1)
dat <- dat[dat$time <= 60, ]
hfr <- get_hfr(data = dat, col = "type", window = iraq_window,
               time_col = "time", time_range = c(1, 60),
               coordinates = c("longitude", "latitude"), combine = FALSE)
hfr$dist_bag <- rep(list(get_dist_focus(window = iraq_window, lon = 44.366,
                                        lat = 33.315, ndim = 64)), nrow(hfr))

# Observed density (propensity score) and counterfactual densities
obs <- get_obs_dens(hfr, dep_var = "airstrike", indep_var = "dist_bag",
                    ndim = 64, window = iraq_window)
base <- get_base_dens(window = iraq_window, ndim = 64,
                      out_data = insurgencies,
                      out_coordinates = c("longitude", "latitude"))
cf1 <- get_cf_dens(expected_number = 2, base_dens = base, window = iraq_window)
cf2 <- get_cf_dens(expected_number = 4, base_dens = base, window = iraq_window)

# Outcome counts by pixel, and CATE over the distance-from-Baghdad modifier
hfr$pc_insurgency <- pixel_count_ppp(hfr$insurgency, ndim = 64)
cate <- get_cate(obs = obs, cf1 = cf1, cf2 = cf2,
                 treat = hfr$airstrike, pixel_count_out = hfr$pc_insurgency,
                 lag = 1, entire_window = iraq_window,
                 em = hfr$dist_bag, nbase = 4)

Sensitivity analysis for conditional average treatment effects

Description

'get_cate_sens()' evaluates how robust conditional average treatment effect (CATE) estimates are to possible unmeasured confounding. The function projects each period-specific weighted surface onto the same effect-modifier basis used by 'get_cate()', and then checks whether each non-intercept basis coefficient can be shifted to zero under each sensitivity parameter 'gamma'.

Usage

get_cate_sens(
  obs,
  cf1,
  cf2,
  treat,
  pixel_count_out,
  lag,
  trunc_level = 0.95,
  time_after = TRUE,
  entire_window = NULL,
  em = NULL,
  E_mat = NULL,
  nbase = 6,
  spline_type = "ns",
  intercept = TRUE,
  eval_values = NULL,
  eval_mat = NULL,
  gamma_vals = seq(1.05, 1.2, by = 0.05),
  save_weights = TRUE,
  tol_slack = 1e-06,
  grid_init = 15,
  max_refine = 5,
  ...
)

Arguments

Details

Unlike 'get_sens()', which returns lower and upper bounds for an average treatment effect, 'get_cate_sens()' checks zero-attainability for the projected coefficients. For each 'gamma', 'zero_attainable' indicates whether the corresponding non-intercept basis coefficient is no longer robust under the current allowance for unmeasured confounding. The 'robust_gamma' value summarizes the largest sensitivity level at which all included coefficients remain robust. The underlying linear programs are solved with 'Rglpk::Rglpk_solve_LP()'.

'gamma = 1' corresponds to no unmeasured confounding. Larger values allow more deviation from the observed treatment process.

Value

list of the following: 'beta': a data frame with 'basis', 'gamma', and 'zero_attainable' for the non-intercept basis coefficients. 'robust_gamma': the smallest coefficient-specific robust gamma across all non-intercept basis coefficients. 'specification': information about the spline basis, evaluated values, and sensitivity parameters.

References

Zhou, L., Imai, K., Lyall, J. and Papadogeorgou, G. (2024). Estimating heterogeneous treatment effects for spatio-temporal causal inference: how economic assistance moderates the effects of airstrikes on insurgent violence. arXiv preprint. doi:10.48550/arXiv.2412.15128

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

Other sensitivity analysis functions: get_sens()

Get counterfactual densities

Description

'get_cf_dens' takes the target (expected) number, baseline density, and power density, and generates a hyperframe with counterfactual densities.

Usage

get_cf_dens(expected_number, base_dens, power_dens = NA, window)

Arguments

Details

There are two ways of generating counterfactual densities. First, users can keep the locations of observations as they are and change the expected number of observations. In this case, users do not have to set 'power_dens' and simply modify 'expected_number'. Alternatively, users can shift the locations as well. In this case, 'power_dens' must be specified. To obtain power densities, refer to [get_power_dens()].

Value

an im object of a counterfactual density

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

[get_obs_dens()], [get_est()]

Other density estimation functions: get_adaptive_baseline_dens(), get_base_dens(), get_cf_dens_adaptive(), get_cf_sum_log_intens(), get_obs_dens(), get_power_dens(), sim_cf_dens(), sim_power_dens()

Examples

# Baseline density from out-of-sample (2007--2008) insurgency data
base <- get_base_dens(window = iraq_window, ndim = 64,
                      out_data = insurgencies,
                      out_coordinates = c("longitude", "latitude"))

# Counterfactual scenario: two airstrikes per day on average,
# distributed proportionally to the baseline density
cf <- get_cf_dens(expected_number = 2, base_dens = base,
                  window = iraq_window)

Get counterfactual densities

Description

'get_cf_dens_adaptive' takes the scale_factor, baseline density to construct counterfactural intensities .

Usage

get_cf_dens_adaptive(baseline_den, scale_factor)

Arguments

Value

a list of the following: * 'intens_grid_cells': im object of counterfactural intensities for each time period * 'estimated_counts': the number of events that is estimated by the poisson point process model for each time period * 'sum_log_intens': the sum of log intensities for each time period

See Also

Other density estimation functions: get_adaptive_baseline_dens(), get_base_dens(), get_cf_dens(), get_cf_sum_log_intens(), get_obs_dens(), get_power_dens(), sim_cf_dens(), sim_power_dens()

Calculate the log counterfactual densities

Description

A function that takes a hyperframe and returns the log counterfactual densities ie, the numerator of the equation

Usage

get_cf_sum_log_intens(cf_dens, treatment_data)

Arguments

Details

'get_cf_sum_log_intens()' evaluates a counterfactual density at the observed treatment locations for each time period using bilinear interpolation ('spatstat.geom::interp.im()'), and returns the sum of the log intensities per period. 'cf_dens' may be a single 'im' object reused across all periods or a list of 'im' objects with one per period. Points falling on the boundary, where the intensity cannot be interpolated, are dropped; a period with no usable points contributes a sum of zero.

Value

A numeric vector of sums of log densities for each time period

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

Other density estimation functions: get_adaptive_baseline_dens(), get_base_dens(), get_cf_dens(), get_cf_dens_adaptive(), get_obs_dens(), get_power_dens(), sim_cf_dens(), sim_power_dens()

Get distance maps

Description

'get_dist_focus()' generates a distance map from focus locations.

Usage

get_dist_focus(
  window,
  lon,
  lat,
  resolution = NULL,
  ndim = NULL,
  mile = FALSE,
  preprocess = FALSE,
  input_crs = 4326,
  unit_scale = 1000
)

Arguments

Details

This function performs its computation using the 'future' framework (via 'furrr'); to run it in parallel, set 'future::plan(future::multisession)' before calling this function. The results are identical regardless of the plan.

Value

an im object

See Also

Other spatial utility functions: conv_owin_into_sf(), get_dist_line(), get_distexp(), get_elev(), get_window()

Get distance maps from lines and polygons

Description

'get_dist_line()' generates a distance map from lines and polygons.

Usage

get_dist_line(
  window,
  path_to_shapefile = NULL,
  line_data = NULL,
  mile = FALSE,
  resolution = NULL,
  ndim = NULL,
  preprocess = TRUE,
  unit_scale = 1000
)

Arguments

Details

The function ensures spatial integrity by automatically projecting the line_data or shapefile to match the Coordinate Reference System (CRS) of the window.

This function performs its computation using the 'future' framework (via 'furrr'); to run it in parallel, set 'future::plan(future::multisession)' before calling this function. The results are identical regardless of the plan.

Value

an im object

See Also

Other spatial utility functions: conv_owin_into_sf(), get_dist_focus(), get_distexp(), get_elev(), get_window()

Get the expectation of treatment events with arbitrary distances

Description

'get_distexp()' takes counterfactual densities and and returns the expected number of treatment events based on distances from a user-specified focus.

Usage

get_distexp(
  cf_sim_results,
  entire_window,
  dist_map,
  dist_map_unit = "km",
  use_raw = FALSE
)

Arguments

Details

'get_distexp()' builds a sequence of nested sub-windows defined by percentiles of the distance map 'dist_map', then integrates each simulated counterfactual density over those sub-windows to obtain the expected number of treatment events within each distance band. By default the expectations are standardized by the total integral of the first counterfactual density; set 'use_raw = TRUE' to return raw expected counts instead. The output is a 'distlist' object suitable for plotting.

Value

A list of resulting dataframe ('result_data'), windows ('window_list'), data for distance quantiles, and a window object for the entire window

See Also

Other spatial utility functions: conv_owin_into_sf(), get_dist_focus(), get_dist_line(), get_elev(), get_window()

Get elevation data

Description

'get_elev()' takes a directory that hosts shapefile and returns an owin object of altitudes.

Usage

get_elev(load_path, ...)

Arguments

Details

'get_elev()' reads a shapefile and downloads elevation data clipped to that region via 'elevatr::get_elev_raster()' (the resolution argument 'z' must be passed through '...'). The raster is then converted into a 'spatstat.geom::im' object, flipping the matrix vertically so that the raster (top-left origin) aligns with the 'spatstat' (bottom-left origin) convention.

Value

an im object (unit: meters)

See Also

Other spatial utility functions: conv_owin_into_sf(), get_dist_focus(), get_dist_line(), get_distexp(), get_window()

convert a list of im objects to a vector

Description

'get_em_vec()' get the vector form of a column of a hyperframe that summarizes the effect modifier data in heterogeneity analysis

Usage

get_em_vec(
  em,
  outcome_pixel_count = NULL,
  time_after = TRUE,
  entire_window = NULL,
  lag
)

Arguments

Details

The function 'get_em_vec()' get the vector form of the effect modifier in the heterogeneity analysis. It is useful if you want to construct the variance matrix 'E_mat' that is passed to the function 'get_cate()'

Value

a numeric vector giving the effect modifier values, flattened across pixels and time periods, with values outside 'entire_window' (if supplied) set to 'NA'.

References

Zhou, L., Imai, K., Lyall, J. and Papadogeorgou, G. (2024). Estimating heterogeneous treatment effects for spatio-temporal causal inference: how economic assistance moderates the effects of airstrikes on insurgent violence. arXiv preprint. doi:10.48550/arXiv.2412.15128

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

Other data preparation functions: get_hfr(), get_hist(), imls_to_arr(), pixel_count_ppp(), smooth_ppp()

Get causal estimates comparing two scenarios

Description

'get_est()' generates causal estimates comparing two counterfactual scenarios.

Usage

get_est(
  obs,
  cf1,
  cf2,
  treat,
  sm_out,
  mediation = FALSE,
  obs_med_log_sum_dens = NA,
  cf1_med_log_sum_dens = NA,
  cf2_med_log_sum_dens = NA,
  lag,
  time_after = TRUE,
  entire_window,
  use_dist,
  windows,
  dist_map,
  dist,
  trunc_level = NA,
  save_weights = TRUE
)

Arguments

Details

The level of truncation indicates the quantile of weights at which weights are truncated. That is, if 'trunc_level = 0.95', then all weights are truncated at the 95 percentile of the weights.

Value

list of the following: 'cf1_ave_surf': average weighted surface for scenario 1 'cf2_ave_surf': average weighted surface for scenario 2 'est_cf': estimated effects of each scenario 'est_causal': estimated causal contrasts 'var_cf': variance upper bounds for each scenario 'var_causal': variance upper bounds for causal contrasts 'windows': list of owin objects

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

[get_obs_dens()], [get_cf_dens()], [get_sens()]

Other causal effect estimation functions: get_cate(), get_estimates(), get_var_bound(), get_weighted_surf()

Examples

# Prepare data: airstrikes (treatment) and insurgencies (outcome), Iraq 2006
dat <- rbind(airstrikes_2006[airstrikes_2006$type == "Airstrike", ],
             insurgencies_2006)
dat$type <- ifelse(dat$type == "Airstrike", "airstrike", "insurgency")
dat$time <- as.numeric(dat$date - min(dat$date) + 1)
dat <- dat[dat$time <= 60, ]
hfr <- get_hfr(data = dat, col = "type", window = iraq_window,
               time_col = "time", time_range = c(1, 60),
               coordinates = c("longitude", "latitude"), combine = FALSE)
dist_baghdad <- get_dist_focus(window = iraq_window, lon = 44.366,
                               lat = 33.315, ndim = 64)
hfr$dist_bag <- rep(list(dist_baghdad), nrow(hfr))

# Observed density (propensity score) and counterfactual densities
obs <- get_obs_dens(hfr, dep_var = "airstrike", indep_var = "dist_bag",
                    ndim = 64, window = iraq_window)
base <- get_base_dens(window = iraq_window, ndim = 64,
                      out_data = insurgencies,
                      out_coordinates = c("longitude", "latitude"))
cf1 <- get_cf_dens(expected_number = 2, base_dens = base, window = iraq_window)
cf2 <- get_cf_dens(expected_number = 4, base_dens = base, window = iraq_window)

# Smoothed outcomes
hfr$sm_insurgency <- smooth_ppp(hfr$insurgency, method = "abramson", ndim = 64)

# Causal estimates comparing the two scenarios
est <- get_est(obs = obs, cf1 = cf1, cf2 = cf2,
               treat = hfr$airstrike, sm_out = hfr$sm_insurgency,
               lag = 1, entire_window = iraq_window,
               use_dist = TRUE, dist_map = dist_baghdad,
               dist = c(100, 200, 300), trunc_level = 0.95)

Generate a Hajek estimator

Description

A function that returns a Hajek estimator of causal contrasts

Usage

get_estimates(
  weighted_surf_1,
  weighted_surf_2,
  use_dist = TRUE,
  windows,
  dist_map,
  dist,
  entire_window
)

Arguments

Details

'get_estimates()' is an internal function to 'get_est()' function, performing the estimation analysis after 'get_weighted_surf()' function

Value

list of Hajek estimators for each scenario ('est_haj'), causal contrasts (Hajek estimator) as a matrix ('est_tau_haj_matrix'), and causal contrast (scenario 2 - scenario 1) as a numeric vector ('est_tau_haj_cf2_vs_cf1'), along with weights, windows, and smoothed outcomes

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

Other causal effect estimation functions: get_cate(), get_est(), get_var_bound(), get_weighted_surf()

Create a hyperframe

Description

'get_hfr()' takes a dataframe with time and location variables and generates a hyperframe with point patterns.

Usage

get_hfr(
  data,
  col,
  window,
  time_col,
  time_range,
  coordinates = c("longitude", "latitude"),
  combine = TRUE,
  input_crs = 4326,
  unit_scale = 1000,
  check_duplicates = FALSE
)

Arguments

Details

Event data often contain multiple events at identical coordinates (e.g., several events recorded at the same location within one time period). Such duplicated points are legitimate observations and are retained as they are; each point contributes separately to subsequent intensity estimation. For this reason, ‘get_hfr()' skips 'spatstat'’s duplicate-point check by default ('check_duplicates = FALSE'), so the warning "data contain duplicated points" is not issued. Set 'check_duplicates = TRUE' to re-enable the check as a diagnostic for potential data-recording issues. Downstream functions that pool points across time periods (e.g., 'get_hist()', 'smooth_ppp()', 'get_base_dens()', 'dx_supthin()') always skip the check, since duplicates are unavoidable there.

Value

A hyperframe is generated with rows representing time and columns representing the following: * The first column: time variable * The middle columns: ppp objects (see 'spatstat.geom::ppp()') generated for each subtype of events of interest * The last column (if 'combine = TRUE'): ppp objects with all subtypes combined. This column is named as 'all_combined'.

See Also

[get_window()], [smooth_ppp()]

Other data preparation functions: get_em_vec(), get_hist(), imls_to_arr(), pixel_count_ppp(), smooth_ppp()

Examples

# Data
dat <- data.frame(time = c(1, 1, 2, 2),
                  longitude = c(43.9, 44.5, 44.1, 44.0),
                  latitude = c(33.6, 32.7, 33.6, 33.5),
                  type = rep(c("treat", "out"), 2))

# Hyperframe
get_hfr(data = dat,
        col = "type",
        window = iraq_window,
        time_col = "time",
        time_range = c(1, 2),
        coordinates = c("longitude", "latitude"),
        combine = FALSE)

Obtain histories of treatment or outcome events

Description

'get_hist()' takes a hyperframe and time and columns of interest, and generates histories of events of interest.

Usage

get_hist(tt, Xt, Yt = NA, lag, window, x_only = TRUE)

Arguments

Value

list of treatment and outcome histories

See Also

Other data preparation functions: get_em_vec(), get_hfr(), imls_to_arr(), pixel_count_ppp(), smooth_ppp()

Examples

dat_out <- insurgencies[1:100, ]
dat_out$time <- as.numeric(dat_out$date - min(dat_out$date) + 1)

# Hyperframe
dat_hfr <- get_hfr(data = dat_out,
                   col = "type",
                   window = iraq_window,
                   time_col = "time",
                   time_range = c(1, max(dat_out$time)),
                   coordinates = c("longitude", "latitude"),
                   combine = TRUE)

# Histories
lapply(1:nrow(dat_hfr), get_hist,
       Xt = dat_hfr$all_outcome,
       lag = 1, window = iraq_window)

Solve linear program for sensitivity bounds at a given gamma

Description

Solves the pair of linear programs that yield the upper and lower bounds of the Hajek-weighted estimand under a given sensitivity parameter 'gamma'. Used internally by 'get_sens()'.

Usage

get_linear_prog(wto, this_gamma)

Arguments

Details

'get_linear_prog()' is an internal function to 'get_sens()'. It relies on 'Rglpk::Rglpk_solve_LP()' to solve the transformed linear program.

Value

a tibble with columns 'high' and 'low' giving the upper and lower bounds of the estimand at 'this_gamma'.

Generate observed densities

Description

'get_obs_dens()' takes a hyperframe and returns observed densities. The output is used as propensity scores.

Usage

get_obs_dens(hfr, dep_var, indep_var, ndim = 128, resolution = NULL, window)

Arguments

Details

'get_obs_dens()' assumes the poisson point process model and calculates observed densities for each time period. It depends on 'spatstat.model::mppm()'. Users should note that the coefficients in the output are not directly interpretable, since they are the coefficients inside the exponential of the poisson model.

Value

list of the following: * 'indep_var': independent variables * 'coef': coefficients * 'deviance': deviance * 'null_deviance': null deviance * 'dispersion': dispersion parameter * 'res_df': average residuals as a dataframe * 'intens_grid_cells': im object of observed densities for each time period * 'estimated_counts': the number of events that is estimated by the poisson point process model for each time period * 'sum_log_intens': the sum of log intensities for each time period * 'actual_counts': the number of events (actual counts) * 'window': window object used as an input

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

[get_cf_dens()], [get_est()]

Other density estimation functions: get_adaptive_baseline_dens(), get_base_dens(), get_cf_dens(), get_cf_dens_adaptive(), get_cf_sum_log_intens(), get_power_dens(), sim_cf_dens(), sim_power_dens()

Examples

# Prepare data: airstrikes (treatment) and insurgencies (outcome), Iraq 2006
dat <- rbind(airstrikes_2006[airstrikes_2006$type == "Airstrike", ],
             insurgencies_2006)
dat$type <- ifelse(dat$type == "Airstrike", "airstrike", "insurgency")
dat$time <- as.numeric(dat$date - min(dat$date) + 1)
dat <- dat[dat$time <= 60, ]
hfr <- get_hfr(data = dat, col = "type", window = iraq_window,
               time_col = "time", time_range = c(1, 60),
               coordinates = c("longitude", "latitude"), combine = FALSE)

# Covariate surface: distance from Baghdad
hfr$dist_bag <- rep(list(get_dist_focus(window = iraq_window, lon = 44.366,
                                        lat = 33.315, ndim = 64)), nrow(hfr))

# Observed density of the treatment (propensity score)
obs <- get_obs_dens(hfr, dep_var = "airstrike", indep_var = "dist_bag",
                    ndim = 64, window = iraq_window)

Get power densities

Description

'get_power_dens()' takes the target densities and their priorities and returns a power density.

Usage

get_power_dens(target_dens, priorities, window)

Arguments

Details

'get_power_dens()' raises each target density to the power given by the corresponding entry of 'priorities', multiplies the results together, and normalizes the product to integrate to one over 'window'. The resulting power density is used to shift the locations of counterfactual events relative to the baseline density.

Value

an im object of power densities

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

[get_cf_dens()], [sim_power_dens()]

Other density estimation functions: get_adaptive_baseline_dens(), get_base_dens(), get_cf_dens(), get_cf_dens_adaptive(), get_cf_sum_log_intens(), get_obs_dens(), sim_cf_dens(), sim_power_dens()

Examples

# A target density: proportional to the distance from Baghdad
dist_baghdad <- get_dist_focus(window = iraq_window,
                               lon = 44.366, lat = 33.315, ndim = 64)
power <- get_power_dens(target_dens = list(dist_baghdad / sum(dist_baghdad)),
                        priorities = 1, window = iraq_window)

Sensitivity analysis for counterfactual contrasts

Description

'get_sens()' computes bounds on the causal contrast between two counterfactual densities across a grid of sensitivity parameters 'gamma'. At each value of 'gamma', linear programming is used to obtain worst-case upper and lower bounds of the Hajek-weighted estimand for each scenario; the returned bounds describe how robust the causal contrast is to possible violations of the no-unmeasured-confounding assumption.

Usage

get_sens(
  obs,
  cf1,
  cf2,
  treat,
  sm_out,
  lag,
  entire_window,
  window,
  gamma_vals = seq(1, 1.2, by = 0.01),
  time_after = TRUE,
  trunc_level = NA,
  tol_slack = 1e-06,
  grid_init = 15,
  max_refine = 5
)

Arguments

Details

'gamma = 1' corresponds to no unmeasured confounding and recovers point estimates analogous to those of 'get_est()'. As 'gamma' increases, the bounds widen, reflecting greater allowance for unobserved confounding. The 'lb' and 'ub' columns retain the conservative bounds from the original implementation. The 'zero_attainable' column indicates whether the result is no longer robust under the current value of 'gamma', or equivalently under the current allowance for unmeasured confounding. The underlying linear programs are solved with 'Rglpk::Rglpk_solve_LP()'.

This function performs its computation using the 'future' framework (via 'furrr'); to run it in parallel, set 'future::plan(future::multisession)' before calling this function. The results are identical regardless of the plan.

Value

a tibble with columns: * 'gamma': the sensitivity parameter * 'lb': lower bound on the causal contrast at 'gamma' * 'ub': upper bound on the causal contrast at 'gamma' * 'zero_attainable': whether zero is attainable at 'gamma' * 'robust_gamma': the largest gamma at which zero is not attainable

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

Other sensitivity analysis functions: get_cate_sens()

Calculate variance upper bounds

Description

A function that calculates variance upper bounds

Usage

get_var_bound(estimates)

Arguments

Details

'get_var_bound()' is an internal function to 'get_estimates()' function, performing the estimation analysis after 'get_est()' function.

Value

list of variance upper bounds for each scenario ('bound_haj') and causal contrasts ('bound_tau_haj'). Note that this function returns variance upper bounds for Hajek estimators

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

Other causal effect estimation functions: get_cate(), get_est(), get_estimates(), get_weighted_surf()

Generate average weighted surfaces

Description

A function that returns averaged weighted surfaces (both IPW and Hajek) along with weights

Usage

get_weighted_surf(
  obs_dens,
  cf_dens,
  mediation = FALSE,
  cate = FALSE,
  obs_med_log_sum_dens,
  cf_med_log_sum_dens,
  treatment_data,
  smoothed_outcome,
  lag,
  entire_window,
  time_after,
  truncation_level = truncation_level
)

Arguments

Details

'get_weighted_surf()' is an internal function to 'get_estimates()' function. If 'time_after' is TRUE, then this function uses treatment data and weights from lag to nrow(data)-1, and outcome data from lag+1 to nrow(data).

This function performs its computation using the 'future' framework (via 'furrr'); to run it in parallel, set 'future::plan(future::multisession)' before calling this function. The results are identical regardless of the plan.

Value

list of an average weighted surface ('avarage_surf', an 'im' object), a Hajek average weighted surface ('average_weighted_surf_haj', an 'im' object), weights, and smoothed outcomes

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

Other causal effect estimation functions: get_cate(), get_est(), get_estimates(), get_var_bound()

Generate a window

Description

'get_window()' takes a directory that hosts a shapefile and returns an owin object.

Usage

get_window(load_path, target_crs = NULL, unit_scale = 1000)

Arguments

Details

'get_window()' reads a shapefile and converts its boundary into a 'spatstat.geom::owin' object. When 'target_crs' is not supplied and the data are in longitude/latitude, a Cartesian CRS is suggested automatically via 'crsuggest::suggest_crs()' and the geometry is projected accordingly. Polygon vertices are reordered to anti-clockwise as required by 'owin', the window is rescaled by 'unit_scale' (so the default unit becomes kilometers), and the CRS is stored as an attribute for downstream functions.

Value

owin object

See Also

[get_hfr()]

Other spatial utility functions: conv_owin_into_sf(), get_dist_focus(), get_dist_line(), get_distexp(), get_elev()

Examples

# An example window from the shapefile shipped with the sf package
win <- get_window(load_path = system.file("shape/nc.shp", package = "sf"),
                  target_crs = 32119)

convert a list of im objects to a three-dimensional array

Description

'imls_to_arr()' convert a list of im object to a 3D array

Usage

imls_to_arr(imls, start = 1, end = NULL, entire_window = NULL, ...)

Arguments

Details

'imls_to_arr()' is a internal function for 'imls_to_vec()'. By default, it returns a three-dimensional array of dimension n by m byl where n and m are the dimensions of the im objects, and l is the length of the list. All the im objects in the list need to have the same dimensions.

Value

a three-dimensional array of dimension n by m by l, where n and m are the pixel dimensions of the 'im' objects and l is the number of selected list elements. When 'entire_window' is supplied, cells outside that window are set to 'NA'.

See Also

Other data preparation functions: get_em_vec(), get_hfr(), get_hist(), pixel_count_ppp(), smooth_ppp()

insurgencies

Description

A dataset of insurgencies data in Iraq (February to July 2007)

Usage

insurgencies

Format

A tibble with 68573 rows and 4 variables:

date

Date (YYYY-MM-DD)

longitude

Longitudes (decimal)

latitude

Latitudees (decimal)

type

Types of insurgencies (improvised explosive devices (IED), small arms fire (SAF), or other)

Examples

insurgencies

insurgencies_2006

Description

A dataset of insurgencies data in Iraq in 2006 (2006/1/1-2006/9/24)

Usage

insurgencies_2006

Format

A tibble with 37701 rows and 4 variables:

date

Date (YYYY-MM-DD)

longitude

Longitudes (decimal)

latitude

Latitudees (decimal)

type

Types of insurgencies (improvised explosive devices (IED), small arms fire (SAF), or other)

Examples

insurgencies_2006

iraq_window

Description

An owin object of Iraq

Usage

iraq_window

Format

A polygonal object:

type

Polygonal

xrange

Range (longitude)

yrange

Range (latitude)

bdry

Boundaries

units

Units

Examples

iraq_window

Get number of events in a pixel

Description

'pixel_count_ppp()' takes a column of hyperframes (ppp objects) and gets the number of events in each pixel.

Usage

pixel_count_ppp(
  data,
  resolution = NULL,
  ndim = NULL,
  W = NULL,
  weights = NULL,
  DivideByPixelArea = FALSE,
  ...
)

Arguments

Details

This function performs its computation using the 'future' framework (via 'furrr'); to run it in parallel, set 'future::plan(future::multisession)' before calling this function. The results are identical regardless of the plan.

Value

im objects

See Also

Other data preparation functions: get_em_vec(), get_hfr(), get_hist(), imls_to_arr(), smooth_ppp()

Examples

# Time variable
dat_out <- insurgencies[1:100, ]
dat_out$time <- as.numeric(dat_out$date - min(dat_out$date) + 1)

# Hyperframe
dat_hfr <- get_hfr(data = dat_out,
                   col = "type",
                   window = iraq_window,
                   time_col = "time",
                   time_range = c(1, max(dat_out$time)),
                   coordinates = c("longitude", "latitude"),
                   combine = TRUE)

# Get the number of events for each pixel
pixel_count_ppp(data = dat_hfr$all_combined)

Plot estimated CATE

Description

Plot method for objects of class 'cate', returned by [get_cate()]. Visualizes the estimated conditional average treatment effects (CATE) across the chosen evaluation values, or the estimated regression coefficients, with confidence intervals.

Usage

## S3 method for class 'cate'
plot(
  x,
  ...,
  result = "cate",
  type = "l",
  scale = 1,
  xrange = NULL,
  main = "",
  xlab = "",
  ylim = NULL
)

Arguments

Value

A 'ggplot' object showing the estimated CATE (or regression coefficients) with confidence intervals.

See Also

[get_cate()]

Plot simulated counterfactual densities

Description

Plot method for objects of class 'cflist', returned by [sim_cf_dens()]. Takes the simulated counterfactual densities and their powers and returns a faceted counterfactual density image over the range of parameters.

Usage

## S3 method for class 'cflist'
plot(
  x,
  ...,
  color = c("white", "#F8DAC5FF", "#F4825AFF", "#D2204CFF", "#771F59FF"),
  grayscale = FALSE
)

Arguments

Value

A 'ggplot' object (a faceted arrangement of counterfactual density images, one per power).

See Also

[sim_cf_dens()]

Plot distance-based expectations

Description

Plot method for objects of class 'distlist', returned by [get_distexp()]. Visualizes the expected number (or proportion) of treatment events covered as a function of distance from the focus, and optionally the windows defined by distance quantiles.

Usage

## S3 method for class 'distlist'
plot(
  x,
  ...,
  dist_map_unit = "km",
  grayscale = FALSE,
  win_plot = FALSE,
  use_raw = FALSE
)

Arguments

Value

A 'ggplot' object. If 'win_plot = TRUE', the arranged window plots; otherwise the expectation-versus-distance plot.

See Also

[get_distexp()]

Plot estimates

Description

Plot method for objects of class 'est', returned by [get_est()]. Visualizes the estimated causal effects per time period (point estimates with 90 weighted counterfactual density surfaces.

Usage

## S3 method for class 'est'
plot(x, ..., surface = FALSE, lim = NA)

Arguments

Value

If 'surface = FALSE' (the default), a single 'ggplot' object showing the causal effects per time period. If 'surface = TRUE', a named list with two 'ggplot' objects, 'surface' (the difference in average weighted surfaces) and 'expectation' (the causal effects per time period).

See Also

[get_est()]

Plot a hyperframe

Description

Plot method for objects of class 'hyperframe' (as created by [get_hfr()]). Visualizes the selected point pattern ('ppp') or pixel image ('im') column(s) over the specified time period(s), arranging multiple time periods and/or columns by faceting or combining them.

Usage

## S3 method for class 'hyperframe'
plot(
  x,
  ...,
  col,
  time_col = "time",
  range,
  lim = NA,
  main = "Image object",
  scalename = NA,
  color = c("white", "#F8DAC5FF", "#F4825AFF", "#D2204CFF", "#771F59FF"),
  combined = TRUE
)

Arguments

Value

A 'ggplot' object visualizing the selected column(s) and time period(s).

See Also

[get_hfr()]

Plot a pixel image

Description

Plot method for objects of class 'im' (spatstat pixel images, such as the density images produced by the package's density functions). Renders the image as a filled raster over its observation window, with optional value transformation and grayscale rendering.

Usage

## S3 method for class 'im'
plot(
  x,
  ...,
  main = "Image object",
  scalename = "Density",
  grayscale = "FALSE",
  transf = NULL,
  color = c("white", "#F8DAC5FF", "#F4825AFF", "#D2204CFF", "#771F59FF"),
  lim = NA
)

Arguments

Value

A 'ggplot' object rendering the pixel image.

Plot a list of pixel images

Description

Plot method for objects of class 'imlist' (a list of spatstat pixel images, such as a sequence of density images over time periods). Renders one or more images as filled rasters over their observation window, arranging multiple frames into a common-legend grid.

Usage

## S3 method for class 'imlist'
plot(
  x,
  ...,
  main = "image",
  lim = NA,
  transf = NULL,
  frame = 1,
  scalename = "Density",
  color = c("white", "#F8DAC5FF", "#F4825AFF", "#D2204CFF", "#771F59FF"),
  grayscale = FALSE,
  ncol = NA,
  nrow = NA
)

Arguments

Value

A 'ggplot' object. For a single frame, the rendered image; for multiple frames, an arranged grid of images with a common legend.

Plot a list of pixel images or point patterns

Description

Plot method for objects of class 'list'. If the list contains spatstat pixel images ('im'), they are rendered as filled rasters; if it contains point patterns ('ppp'), the points are plotted over the observation window. Multiple frames are arranged into a grid (images) or combined/faceted (point patterns).

Usage

## S3 method for class 'list'
plot(
  x,
  ...,
  main = "list",
  lim = NA,
  transf = NULL,
  frame = 1,
  combined = TRUE,
  scalename = "Density",
  color = c("white", "#F8DAC5FF", "#F4825AFF", "#D2204CFF", "#771F59FF"),
  grayscale = FALSE,
  ncol = NA,
  nrow = NA
)

Arguments

Value

A 'ggplot' object visualizing the images or point patterns in the list.

Plot observed densities

Description

Plot method for objects of class 'obs', returned by [get_obs_dens()]. Compares actual versus predicted event counts over time, shows the corresponding residuals, and maps the average residual field. Up to three fitted densities can be overlaid for comparison.

Usage

## S3 method for class 'obs'
plot(
  x,
  ...,
  dens_2 = NA,
  dens_3 = NA,
  lim = c(-1, 1),
  time_unit = NA,
  combined = TRUE,
  color_actual = "darkgrey",
  color_dens_1 = "#f68f46ff",
  color_dens_2 = "#593d9cff",
  color_dens_3 = "#efe350ff"
)

Arguments

Value

If 'combined = TRUE' (the default), a single arranged 'ggplot' object combining the comparison, residual, and (when applicable) average-residual-field panels. If 'combined = FALSE', a named list with the underlying data frame ('plot_data') and the individual 'ggplot' objects ('plot_compare', 'plot_residual', 'plot_arf').

See Also

[get_obs_dens()]

Plot simulated power densities

Description

Plot method for objects of class 'powerlist', returned by [sim_power_dens()]. Takes the simulated power densities and their priorities and returns a faceted power density image over the range of parameters.

Usage

## S3 method for class 'powerlist'
plot(
  x,
  ...,
  color = c("white", "#F8DAC5FF", "#F4825AFF", "#D2204CFF", "#771F59FF"),
  grayscale = FALSE
)

Arguments

Value

A 'ggplot' object (a faceted arrangement of power density images).

See Also

[sim_power_dens()]

Plot a list of point patterns

Description

Plot method for objects of class 'ppplist' (a list of spatstat point patterns, such as observed events across time periods). Plots the points over the observation window, either combining multiple time periods into one plot or faceting them.

Usage

## S3 method for class 'ppplist'
plot(x, ..., frame = 1, main = "ppp", combined = TRUE)

Arguments

Value

A 'ggplot' object plotting the selected point pattern(s).

Plot the results of superthinning tests

Description

Plot method for objects of class 'supthin', returned by [dx_supthin()]. Visualizes the observed and simulated-envelope summary functions (the K-function and the centered L-function) used to diagnose departures from complete spatial randomness after superthinning.

Usage

## S3 method for class 'supthin'
plot(x, ...)

Arguments

Value

A named list with two 'ggplot' objects, 'plot_k' (the K-function with simulation envelope) and 'plot_l' (the centered L-function with simulation envelope).

See Also

[dx_supthin()]

Plot weights

Description

Plot method for objects of class 'weights', derived from the estimation produced by [get_est()]. Displays histograms of the (standardized or unstandardized) inverse-probability weights, faceted by intervention.

Usage

## S3 method for class 'weights'
plot(x, ..., type_weights = "standardized", binwidth = NULL)

Arguments

Value

A 'ggplot' object showing histograms of the weights, faceted by intervention.

See Also

[get_est()]

Print results

Description

Print method for objects of class 'cate', returned by [get_cate()]. Builds and returns a data frame of the estimated CATE values at the chosen evaluation points, together with their 90

Usage

## S3 method for class 'cate'
print(x, ...)

Arguments

Details

Currently, observed densities (class: obs), estimates (class: est) and heterogeneity estimates (class: cate) are supported by this function.

Value

A data frame with one row per evaluation value, containing the evaluation value, the point estimate, and the lower/upper bounds of the 90 and 95

See Also

[get_cate()]

Print results

Description

Print method for objects of class 'est', returned by [get_est()]. Builds and returns a data frame of the estimated causal effects per time period, together with their 90

Usage

## S3 method for class 'est'
print(x, ...)

Arguments

Details

Currently, observed densities (class: obs) and estimates (class: est) are supported by this function.

Value

A data frame with one row per window, containing the point estimate and the lower/upper bounds of the 90

See Also

[get_est()]

Generate weighted surfaces for sensitivity analysis

Description

A variant of 'get_weighted_surf()' that retains per-period Hajek weights for both the entire region and a window of interest, so that downstream linear-programming bounds can be computed.

Usage

sens_weighted_surf(
  obs_dens,
  cf_dens,
  treatment_data,
  smoothed_outcome,
  lag,
  entire_window,
  window,
  time_after,
  truncation_level = 0.95
)

Arguments

Details

'sens_weighted_surf()' is an internal function used by 'get_sens()'.

Value

list of the following: * 'haj_wt_daily_out': Hajek-weighted daily outcomes integrated over the window of interest * 'haj_weights_window_of_interest': per-period Hajek weights for the window of interest * 'haj_weights_entire_window': per-period Hajek weights for the entire window

Simulate counterfactual densities

Description

'sim_cf_dens()' takes a list of power densities and returns simulated counterfactual densities.

Usage

sim_cf_dens(expected_number, base_dens, power_sim_results, window)

Arguments

Details

'sim_cf_dens()' combines a baseline density with each of the power densities produced by 'sim_power_dens()'. For every simulated set of priorities, the baseline density is multiplied by the corresponding power density, normalized over 'window', and rescaled to the supplied 'expected_number' of events. The result is a 'cflist' object holding the list of counterfactual densities together with the associated powers and expected number.

Value

list of counterfactual densities, power as numerics, and expected number as a numeric

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

[sim_power_dens()], [get_distexp()]

Other density estimation functions: get_adaptive_baseline_dens(), get_base_dens(), get_cf_dens(), get_cf_dens_adaptive(), get_cf_sum_log_intens(), get_obs_dens(), get_power_dens(), sim_power_dens()

Simulate power densities

Description

A function that takes the target densities and their priorities and returns a power density image over a range of parameters

Usage

sim_power_dens(target_dens, dens_manip, priorities, priorities_manip, window)

Arguments

Details

'sim_power_dens()' generates a sequence of power densities by holding the priorities of the fixed target densities at 'priorities' while varying the priority of 'dens_manip' across the values in 'priorities_manip'. For each such value, the product of the powered target densities is normalized over 'window'. The result is a 'powerlist' object containing the list of power densities and the manipulated priorities, and is typically passed to 'sim_cf_dens()'.

Value

list of densities and priorities

References

Papadogeorgou, G., Imai, K., Lyall, J. and Li, F. (2022). Causal inference with spatio-temporal data: estimating the effects of airstrikes on insurgent violence in Iraq. Journal of the Royal Statistical Society Series B, 84(5), 1969–1999. doi:10.1111/rssb.12548

Mukaigawara, M., Imai, K., Lyall, J. and Papadogeorgou, G. (2025). Spatiotemporal causal inference with arbitrary spillover and carryover effects. arXiv preprint. doi:10.48550/arXiv.2504.03464

See Also

Other density estimation functions: get_adaptive_baseline_dens(), get_base_dens(), get_cf_dens(), get_cf_dens_adaptive(), get_cf_sum_log_intens(), get_obs_dens(), get_power_dens(), sim_cf_dens()

Smooth outcome events

Description

'smooth_ppp()' takes a column of hyperframes (ppp objects) and smoothes them.

Usage

smooth_ppp(
  data,
  method,
  sampling = NA,
  resolution = NULL,
  ndim = NULL,
  ngroups = NULL
)

Arguments

Details

To smooth ppp objects, users can choose either the Gaussian mixture model ('method = "mclust"') or Abramson's adaptive smoothing ('method = "abramson"'). The Gaussian mixture model is essentially the method that performs model-based clustering of all the observed points. In this package, we employ the EII model (equal volume, round shape (spherical covariance)). This means that we model observed points by several Gaussian densities with the same, round shape. This is why this model is called fixed-bandwidth smoothing. This is a simple model to smooth observed points, yet given that analyzing spatiotemporal data is often computationally demanding, it is often the best place to start (and end). Sometimes this process can also take time, which is why the 'sampling' option is included in this function: with 'sampling', the model is initialized with a random subset of the points, which considerably reduces the computation time for large datasets.

Another, more precise, method for smoothing outcomes is adaptive smoothing ('method = "abramson"'). This method allows users to vary bandwidths based on 'Abramson (1982)'. Essentially, this model assumes that the bandwidth is inversely proportional to the square root of the target densities. Since the bandwidth is adaptive, the estimation is usually more precise than the Gaussian mixture model. However, the caveat is that this method is often extremely computationally demanding.

Abramson's rule requires a pilot estimate of the spatially varying density, which 'smooth_ppp()' obtains automatically as follows. First, the points of all time periods are pooled into a single point pattern. Second, a global bandwidth is selected for this pooled pattern by Scott's rule of thumb ('spatstat.explore::bw.scott()', with separate bandwidths for the two coordinates), and the pilot density is estimated by fixed-bandwidth Gaussian kernel smoothing of the pooled pattern with these bandwidths. Third, point-specific bandwidths are computed with 'spatstat.explore::bw.abram.ppp()' following the inverse-square-root rule, h(u) = h_0 \min\{\tilde{f}(u)^{-1/2}/\gamma, \mathrm{trim}\}, where h_0 is the global bandwidth (the mean of the two Scott bandwidths), \tilde{f}(u) is the pilot density, \gamma is the geometric mean of the \tilde{f}(u)^{-1/2} terms over the observed points (which puts h_0 on the scale of a fixed bandwidth), and the trimming value (5, the 'spatstat' default) prevents excessively large bandwidths at isolated points (Hall and Marron, 1988). Finally, the point-specific bandwidths are assigned back to the points of each time period, and each time period is smoothed by 'spatstat.univar::densityAdaptiveKernel()' with these bandwidths.

Parallel computation: 'smooth_ppp()' smooths the point patterns of all time periods using the 'future' framework (via 'furrr'), which runs sequentially unless a parallel backend is registered. To smooth the time periods in parallel, set a parallel plan before calling this function, e.g., 'future::plan(future::multisession)'. The results are identical regardless of the plan. Parallelization is most beneficial for 'method = "abramson"', whose computation time is dominated by the adaptive smoothing of each time period; for 'method = "mclust"', the model fitting itself is not parallelized, and the one-time cost of launching the parallel workers may outweigh the gains for the (fast) smoothing stage.

Value

im objects as a list

References

Abramson, I. S. (1982). On bandwidth variation in kernel estimates — a square root law. The Annals of Statistics, 10(4), 1217–1223.

Hall, P. and Marron, J. S. (1988). Variable window width kernel density estimates of probability densities. Probability Theory and Related Fields, 80, 37–49.

Scott, D. W. (1992). Multivariate Density Estimation: Theory, Practice and Visualization. New York: Wiley.

See Also

Other data preparation functions: get_em_vec(), get_hfr(), get_hist(), imls_to_arr(), pixel_count_ppp()

Examples

# Insurgency outcomes in Iraq, 2006 (first 60 days)
dat <- insurgencies_2006
dat$time <- as.numeric(dat$date - min(dat$date) + 1)
dat <- dat[dat$time <= 60, ]
hfr <- get_hfr(data = dat, col = "type", window = iraq_window,
               time_col = "time", time_range = c(1, 60),
               coordinates = c("longitude", "latitude"), combine = TRUE)

# Adaptive smoothing of the outcomes
# (to run in parallel, call future::plan(future::multisession) first)
smoothed <- smooth_ppp(hfr$all_combined, method = "abramson", ndim = 64)

Summarize results

Description

Summary method for objects of class 'cate', returned by [get_cate()]. Summarizes the estimated regression coefficients, the CATE evaluated at the chosen values (both with 90 test of whether at least one non-intercept coefficient differs from zero.

Usage

## S3 method for class 'cate'
summary(object, ..., significance_level = 0.05)

Arguments

Details

Currently, observed densities (class: obs), estimates (class: est) and heterogeneity estimates (class: cate) are supported by this function.

Value

A named list with three elements: 'result_betas', a data frame of the estimated regression coefficients with 90 'result_values', a data frame of the CATE evaluated at the chosen values with 90 chi-square statistic, its p-value, the significance level, and the test decision.

See Also

[get_cate()]

Summarize results

Description

Summary method for objects of class 'est', returned by [get_est()]. Summarizes the estimated causal effects per time period (with 90 confidence intervals) together with the associated windows.

Usage

## S3 method for class 'est'
summary(object, ...)

Arguments

Details

Currently, observed densities (class: obs) and estimates (class: est) are supported by this function.

Value

A named list with two elements: 'result', a data frame of the point estimates and 90 of windows used in estimation.

See Also

[get_est()]

Summarize results

Description

Summary method for objects of class 'obs', returned by [get_obs_dens()]. Prints a short summary of the fitted observed-density model (dispersion parameter, deviance, and null deviance) and returns the estimated model coefficients.

Usage

## S3 method for class 'obs'
summary(object, ...)

Arguments

Details

Currently, observed densities (class: obs) and estimates (class: est) are supported by this function.

Value

The estimated model coefficients ('object$coef'), returned alongside the printed model summary.

See Also

[get_obs_dens()]