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Description

This function presents a summary with the pixel quantity of each category present in a categorical raster. It provides spatial screening functionality to quickly understand the composition of a single land use/cover map.

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Usage

summary_map(path)

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Arguments

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path
character, RasterLayer, or RasterStack
The path for the raster to be analysed. If path is a multilayer raster, only the first RasterLayer will be analysed.

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Value

Returns a tibble containing pixel counts for each category:
  • pixvalue: The unique pixel values (category codes) in the raster
  • Qt: The quantity (count) of pixels for each category

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Details

The function accepts input in three formats:
  1. Character path: File path to a raster file (loaded using raster::raster())
  2. RasterLayer: A single raster layer object
  3. RasterStack/RasterBrick: Uses only the first layer from the stack
This function is particularly useful for:
  • Quick quality control of categorical raster data
  • Understanding the distribution of land use/cover categories
  • Verifying that all expected categories are present in a map
  • Calculating area statistics when combined with pixel size information

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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 the first layer
summary_2002 <- summary_map(SaoLourencoBasin[[1]])
print(summary_2002)

# Example output:
# # A tibble: 11 × 2
#   pixvalue     Qt
#      <dbl>  <dbl>
# 1        1 123456
# 2        2  98765
# 3        3  45678
# ...

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See Also

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