`imagesc`

Displays a matrix as an image with values scaled to the full colormap.

Syntax

imagesc(C)

Displays C, mapping its minimum and maximum to the ends of the colormap.

imagesc(x, y, C)

Also sets the pixel coordinates.

imagesc(___, clims)

Uses [cmin cmax] as the color limits instead of the data range.

h = imagesc(___)

Returns the image object.

Description

Think of imagesc as image with scaling: it sets the color limits (clim) from the data, so any range of values uses the whole colormap. It is the usual way to visualize a matrix as a heat map; add colorbar to show what the colors mean.

Input arguments

C: Matrix of values, any real numeric class.
clims: Two-element vector with the values mapped to the first and last colors.

Output arguments

h: Image object.

Example

Heat map of a matrix

A = magic(5);
h = imagesc(A);
colorbar
disp(size(h.CData))

Output

     5     5

imagesc