84_shaders: Single Channel Shaders

In vectools: Advanced Vector Toolkit

Description

These functions return functions (or a list of functions).
The resulting functions, map a matrix of numeric values to a character matrix of colors.

They are designed for rendering single channel images, and also for rendering multiple channels, separately.
(In contrast to rendering a multichannel image, as a single raster image).

Usage

vt3.linear.shader (col0="black", col1="white", min=0, max=1, reverse=FALSE)

vt3.rgb.shaders ()
vt3.hcl.shaders ()
vt3.hsv.shaders ()

vt3.hue.shader (hmin=0, hmax=360, ..., c=50, l=50, na.col="white")

Arguments

hmin, hmax	Single numeric values, the min and max hue values.
c, l	Single numeric values, the C and L values in HCL color space.
na.col	The color returned for NA values.
col0, col1	Strings, the lower and upper colors.
min, max	The min and max values to interpolate between.
reverse	Logical, if true, it's equivalent to swapping min and max.
...	Ignored.

Value

vt3.linear.shader returns a function.

The others return a list of four functions.

See Also

as.raster.SImage, as.raster.MImage

Examples

colf <- vt3.linear.shader ()
colf (c (0.33, 0.67) )

vectools documentation built on June 7, 2021, 9:08 a.m.