Generate colors for a 3D volume, based on the activation data and a colormap.

Applies the colormap function to the data, then sets the alpha value (transparency) to full in all areas without any activation. Feel free to clip data or whatever before passing it, so that all your no-activation data has the same value.

Usage

vol.overlay.colors.from.activation(
  volume,
  colormap_fn = squash::blueorange,
  no_act_source_value = 0
)

Arguments

volume

a 3D array, the activation data (or p-values, effect sizes, or whatever)

colormap_fn

function, a colormap function

no_act_source_value

numerical scalar, the value from the data in 'volume' that means no activation. The output colors for this value will be set to NA. Set to NULL to not change anything.

Value

a 3D matrix of color strings, with the same dimensions as the input volume

See also

Other volume utility: vol.boundary.box(), vol.imagestack(), vol.merge(), vol.planes(), vol.slice()