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Description

Listing major characteristics of raster inputs. Those characteristics include dimensions, resolution, extent, value ranges (min, max), and the coordinate reference system. This function provides directory-based summaries for quality control and metadata extraction.

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Usage

summary_dir(path)

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Arguments

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path
character or list
The path for the Raster* directory or list of Raster* to be analysed. Can be:
  • A character path to a directory containing .tif files
  • A list of RasterLayer objects

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Value

Returns a tibble with the following columns for each raster:
  • file_name: Name of the raster file or layer
  • xmin: Minimum x coordinate (western edge)
  • xmax: Maximum x coordinate (eastern edge)
  • ymin: Minimum y coordinate (southern edge)
  • ymax: Maximum y coordinate (northern edge)
  • res_x: Resolution in x direction
  • res_y: Resolution in y direction
  • nrow: Number of rows
  • ncol: Number of columns
  • min_val: Minimum pixel value
  • max_val: Maximum pixel value
  • crs: Coordinate reference system (CRS) as character string

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Details

This function is essential for:
  • Quality Control: Verify that all rasters in a time series have consistent properties
  • Metadata Extraction: Document the characteristics of your spatial datasets
  • Preprocessing Checks: Ensure rasters are properly aligned before analysis
  • Data Documentation: Generate summary tables for reports and publications
The function automatically handles two input types:
  1. Directory path: Searches for all .tif files in the specified directory
  2. List of RasterLayers: Processes a pre-loaded list of raster objects
All rasters in a time series analysis should have identical extent, resolution, and CRS. Use this function to verify consistency before running intensity analysis or other temporal analyses.

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Examples

# Download the SaoLourencoBasin dataset
url <- "https://zenodo.org/record/3685230/files/SaoLourencoBasin.rda?download=1"
temp <- tempfile()
download.file(url, temp, mode = "wb")
load(temp)

# Summarize all layers in the stack
raster_summary <- summary_dir(raster::unstack(SaoLourencoBasin))
print(raster_summary)

# Example output:
# # A tibble: 5 × 12
#   file_name  xmin  xmax  ymin  ymax res_x res_y  nrow  ncol min_val max_val crs
#   <chr>     <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <int> <int>   <dbl>   <dbl> <chr>
# 1 SLB_2002  -56.8 -55.2 -17.8 -16.5 0.001 0.001  1300  1600       1      11 +proj=longlat...
# 2 SLB_2008  -56.8 -55.2 -17.8 -16.5 0.001 0.001  1300  1600       1      11 +proj=longlat...
# ...

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See Also

  • summary_map() - Quantitative summary of pixel values for a single raster
  • acc_changes() - Calculate accumulated changes across time series

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