generate_age_pop_raster: Generate Age Population Raster

In AgePopDenom: Model Fine-Scale Age-Structured Population Data using Open-Source Data

Generate Age Population Raster

Description

Creates age-stratified population raster layers from predictor data and gamma distribution parameters. Supports parallel processing and caching of results. The output is a multi-layer raster stack with each layer representing the population proportion for a specific age interval.

Usage

generate_age_pop_raster(
  predictor_data,
  scale_pred,
  shape_pred,
  age_range = c(0, 10),
  age_interval = 1,
  country_code,
  ignore_cache = FALSE,
  output_dir,
  n_cores = parallel::detectCores() - 2
)

Arguments

predictor_data	Data frame containing population and spatial data with columns: country, region, district, pop, web_x, web_y
scale_pred	Matrix of scale parameters for gamma distribution predictions
shape_pred	Matrix of shape parameters for gamma distribution predictions
age_range	Numeric vector of length 2 specifying min and max ages, default c(0,99)
age_interval	Numeric interval size between age groups in years, default 1
country_code	Character ISO3 country code
ignore_cache	Logical whether to ignore cached results, default FALSE
output_dir	Character path to output directory
n_cores	Integer number of cores for parallel processing, default detectCores()-2

Details

The function processes age intervals sequentially, computing population proportions using parallel processing. Results are cached as a GeoTIFF file for future use. The output raster maintains spatial properties of the input data and is suitable for GIS analysis and visualization.

Value

SpatRaster object (terra package) containing multiple layers, where each layer represents the population proportion for an age interval. Layer names indicate the age range (e.g., "Age 0 to 1 years"). The raster uses EPSG:3857 projection with 5000m resolution.

Examples

predictor_data <- data.frame(
 country = rep("CountryX", 100),
 region = rep("RegionA", 100),
 district = rep("District1", 100),
 pop = sample(100:1000, 100, replace = TRUE),
 web_x = runif(100, -100, 100),
 web_y = runif(100, -50, 50)
)

scale_pred <- matrix(runif(100 * 10, 1, 5), nrow = 100, ncol = 10)
shape_pred <- matrix(runif(100 * 10, 1, 5), nrow = 100, ncol = 10)

res <- generate_age_pop_raster(predictor_data,
                       scale_pred,
                       shape_pred,
                       country_code = "COD",
                       output_dir = file.path(tempdir()),
                       n_cores = 1)

AgePopDenom documentation built on April 12, 2025, 1:41 a.m.