predict_spm: Prediction over the same or a different set of regions (or...

In smile: Spatial Misalignment: Interpolation, Linkage, and Estimation

Prediction over the same or a different set of regions (or points).

Description

Realizes predictions that can be useful when researchers are interested in predict a variable observed in one political division of a city (or state) on another division of the same region.

Usage

predict_spm(x, ...)

## S3 method for class 'spm_fit'
predict_spm(x, .aggregate = TRUE, ...)

## S3 method for class 'sf'
predict_spm(x, spm_obj, n_pts, type, outer_poly = NULL, id_var, ...)

Arguments

x	a sf object such that its geometris are either points or polygons.
...	additional parameters
.aggregate	logical. Should the predictions be aggregated? In case the input is only a "fit" object, the aggregation is made over the polygons on which the original data was observed. In case the input x is composed by sf POLYGONS, the aggregation is made over this new partition of the study region.
spm_obj	an object of either class spm_fit or mspm_fit
n_pts	a numeric scalar standing for number of points to form a grid over the whole region to make the predictions
type	character type of grid to be generated. See st_sample in the package sf.
outer_poly	(object) sf geometry storing the "outer map" we want to compute the predictions in.
id_var	if x is a set of POLYGONS (areal data) instead of a set of points, the id_var is the name (or index) of the unique identifier associated to each polygon.

Value

a list of size 4 belonging to the class spm_pred. This list contains the predicted values and the mean and covariance matrix associated with the conditional distribution used to compute the predictions.

Examples

data(liv_lsoa) ## loading the LSOA data
data(liv_msoa) ## loading the MSOA data

msoa_spm <- sf_to_spm(sf_obj = liv_msoa, n_pts = 500,
                      type = "regular", by_polygon = FALSE,
                      poly_ids = "msoa11cd",
                      var_ids = "leb_est")
## fitting model
theta_st_msoa <- c("phi" = 1) # initial value for the range parameter

fit_msoa <-
   fit_spm(x = msoa_spm,
           theta_st = theta_st_msoa,
           model = "matern",
           nu = .5,
           apply_exp  = TRUE,
           opt_method = "L-BFGS-B",
           control    = list(maxit = 500))

pred_lsoa <- predict_spm(x = liv_lsoa, spm_obj = fit_msoa, id_var = "lsoa11cd")

smile documentation built on April 29, 2022, 9:05 a.m.