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r.colors.stddev

Sets color rules based on stddev from a raster map's mean value.

r.colors.stddev [-bz] map=name [--verbose] [--quiet] [--qq] [--ui]

Example:

r.colors.stddev map=name

grass.script.run_command("r.colors.stddev", map, flags=None, verbose=None, quiet=None, superquiet=None)

Example:

gs.run_command("r.colors.stddev", map="name")

grass.tools.Tools.r_colors_stddev(map, flags=None, verbose=None, quiet=None, superquiet=None)

Example:

tools = Tools()
tools.r_colors_stddev(map="name")

This grass.tools API is experimental in version 8.5 and expected to be stable in version 8.6.

Parameters

map=name [required]
    Name of raster map
-b
    Color using standard deviation bands
-z
    Force center at zero
--help
    Print usage summary
--verbose
    Verbose module output
--quiet
    Quiet module output
--qq
    Very quiet module output
--ui
    Force launching GUI dialog

map : str, required
    Name of raster map
    Used as: input, raster, name
flags : str, optional
    Allowed values: b, z
    b
        Color using standard deviation bands
    z
        Force center at zero
verbose : bool, optional
    Verbose module output
    Default: None
quiet : bool, optional
    Quiet module output
    Default: None
superquiet : bool, optional
    Very quiet module output
    Default: None

map : str | np.ndarray, required
    Name of raster map
    Used as: input, raster, name
flags : str, optional
    Allowed values: b, z
    b
        Color using standard deviation bands
    z
        Force center at zero
verbose : bool, optional
    Verbose module output
    Default: None
quiet : bool, optional
    Quiet module output
    Default: None
superquiet : bool, optional
    Very quiet module output
    Default: None

Returns:

result : grass.tools.support.ToolResult | None
If the tool produces text as standard output, a ToolResult object will be returned. Otherwise, None will be returned.

Raises:

grass.tools.ToolError: When the tool ended with an error.

DESCRIPTION

r.colors.stddev set raster map color rules based on standard deviations from a map's mean value, either as a continuous color gradient or in color bands per standard deviation (S.D.) from the mean.

With the color band option values less that 1 S.D. from the mean are colored green, within 1-2 S.D. are colored yellow, within 2-3 S.D. are colored red, and beyond 3 S.D. are colored black.

For a differences map there is an option to lock the center of the color table at zero. Values more than two S.D. below the mean will be colored blue; values below the mean but less than 2 S.D. away will transition to white, and above the mean the colors will similarly transition to full red at +2 S.D.

EXAMPLE

North Carolina sample dataset:

g.region raster=elevation -p
r.colors.stddev elevation

r.colors.stddev example
Figure: Standard deviations from mean elevation

SEE ALSO

r.colors, r.univar, v.colors

AUTHOR

Hamish Bowman, Dunedin, New Zealand

SOURCE CODE

Available at: r.colors.stddev source code (history)
Latest change: Monday May 19 11:52:48 2025 in commit 01f1bb4