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PRIOGRID

A comprehensive R package for accessing and transforming spatial-temporal data for conflict research at the PRIO-GRID resolution.

Installation

Install PRIOGRID from GitHub using remotes or renv:

install.packages("renv")
renv::install("prio-data/priogrid")

Troubleshooting Installation

PRIOGRID depends on several spatial libraries (terra, sf, and exactextractr) that require system-level geo-libraries. If installation fails, please refer to the installation guides for these dependencies:

If you continue to experience issues after following these guides, please file an issue.

Initial Setup

PRIOGRID stores settings locally that persist across R sessions. Before using the package, configure where PRIOGRID will store downloaded raw data and transformed datasets:

# Set the folder for PRIOGRID data storage
pgoptions$set_rawfolder("/path/to/your/data/folder")

# Configure temporal settings (optional)
pgoptions$set_start_date(as.Date("1990-12-31"))
pgoptions$set_end_date(as.Date("2023-12-31"))

# View your configuration
pg_dates()
pg_date_intervals()
prio_blank_grid()

Default Settings

  • Spatial resolution: 0.5×0.5 degrees
  • Projection: EPSG:4326 (WGS84)
  • Temporal resolution: 1 year
  • Temporal extent: 1850 to present (where data exists)

Note: When setting dates, use the last day of your desired temporal increment. For example, use 1850-12-31 for yearly data instead of 1850-01-01.

Basic Usage

Download and Read PRIOGRID Data

The simplest workflow involves downloading the complete PRIOGRID dataset and reading it into R:

# Download the latest PRIOGRID dataset to your local folder
download_priogrid()

# Read the dataset into memory
df <- read_priogrid()

# Explore the data
View(df)

Citing Data Sources

Always cite the original data providers. Most data licenses require attribution (e.g., CC-BY), and proper citation is fundamental to good research practice.

When using PRIOGRID data with original variable names, retrieve all necessary citations with:

Advanced Usage

Working with Original Data Sources

For users who need to transform data to custom specifications or work with original source data:

# View available data sources
View(pgsources)

# List all downloadable files
files_to_download <- pg_rawfiles()

# Download specific sources
ucdp_files <- pg_rawfiles() |> 
  dplyr::filter(source_name == "UCDP GED")
download_pg_rawdata(file_info = ucdp_files)

Reading and Transforming Source Data

Each data source has dedicated functions for reading and transformation. Large files use memory-efficient processing via terra:

# Read population data
r <- read_ghsl_population_grid()

# Calculate travel time with custom aggregation
ttime_max <- calc_traveltime(aggregation_function = "max")

Source-specific transformation functions are documented in the corresponding R/data_[source].R files.

Customizing Spatial and Temporal Resolution

PRIOGRID supports flexible spatial and temporal configurations:

Temporal Resolution Examples 

# Monthly data
pgoptions$set_start_date(as.Date("2022-12-31"))
pgoptions$set_temporal_resolution("1 month")
r_monthly <- gen_cru_tmp()

# Quarterly data
pgoptions$set_temporal_resolution("1 quarter")
r_quarterly <- gen_cru_tmp()

Spatial Resolution Examples 

# Lower resolution with custom extent
pgoptions$set_ncol(36)
pgoptions$set_nrow(18)
pgoptions$set_extent(c("xmin" = 0, "xmax" = 180, "ymin" =  0, "ymax" = 90))
r_low_res <- gen_cru_tmp()
plot(r_low_res)

# Compare different resolutions
pgoptions$set_ncol(360)
pgoptions$set_nrow(180)
pgoptions$set_extent(c("xmin" = -180, "xmax" = 180, "ymin" =  -90, "ymax" = 90))
plot(prio_blank_grid())  # High resolution

pgoptions$set_ncol(36)
pgoptions$set_nrow(18)
plot(prio_blank_grid())  # Low resolution

Important: When changing spatial resolution, extent, or projection, PRIOGRID IDs will differ from the default configuration. These custom IDs should only be used within datasets sharing the same spatial configuration.

Contributing

We welcome contributions. Report issues or suggest new data sources or variable ideas using our Issue Tracker.

Please see our contribution guidelines for details on how you can contribute with code.