MATLAB Function Reference Volume 1: A - E - Bad Request

each time they render. CData values equal to or less than cmin map to the first
color value in the colormap, and CData values equal to or greater than cmax
map to the last color value in the colormap. MATLAB performs the following
linear transformation on the intermediate values (referred to as C below) to
map them to an entry in the colormap (whose length is m, and whose row index
is referred to as index below).
index = fix((C–cmin)/(cmax–cmin)∗m)+1
Examples Create (X,Y,Z) data for a sphere and view the data as a surface.
[X,Y,Z] = sphere;
C = Z;
surf(X,Y,Z,C)
Values of C have the range [−1 1]. Values of C near −1 are assigned the lowest
values in the colormap; values of C near 1 are assigned the highest values in
the colormap.
To map the top half of the surface to the highest value in the color table, use
caxis([−1 0])
To use only the bottom half of the color table, enter
caxis([−1 3])
which maps the lowest CData values to the bottom of the colormap, and the
highest values to the middle of the colormap (by specifying a cmax whose value
is equal to cmin plus twice the range of the CData).
The command
caxis auto
resets axis scaling back to auto-ranging and you see all the colors in the
surface. In this case, entering
caxis
returns
[–1 1]
caxis
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