caxis([cmin cmax])caxis autov = caxis;caxis(caxis)
caxis provides an easy way to manipulate the CLim and CLimMode properties of axes objects. Pseudocolor plotting functions, such as mesh, surf, and pcolor, create surface and patch objects which map specified color arrays into colormaps to produce color values. This mapping is controlled by the ColorMap, CLim, and CLimMode properties.
caxis([cmin cmax]) sets the Clim color axis scaling parameters to the specified low and high values. Any values in a color array outside the interval cmin <= c <= cmax are clipped; that is, the corresponding patches or pixels are not plotted.
caxis auto, the default, sets CLimMode to indicate that the color axis scaling parameters are computed automatically using the minimum and maximum of the color array specified in the particular pseudocolor plotting function. In this case, only color values set to Inf or NaN are clipped.
v = caxis returns a two-element row vector v containing the [cmin cmax] currently in use.
caxis(caxis) freezes the color axis scaling at the current limits, so that if hold is turned on, subsequent plots use the same limits.
c be a color array which is the last argument to the mesh, surf, or pcolor function. If caxis auto is in effect, let cmin = min(c) and cmax = max(c). Let m = length(map).
The following linear transformation maps c onto k, an array of indices in the range 1 <= k <= m, with c = cmin mapping to k = 1 and c = cmax mapping to k = m.
If cmin <= c < cmax, then
k = fix((c-cmin)/(cmax-cmin)*m)+1.
If c == cmax, then
k = m.
If c < cmin,c > cmax, or c == NaN, then
k = 'invisible'.
(X,Y,Z) data for a sphere of radius 1, enter
In this case, values of[X,Y,Z] = sphere(32);C = Z;
C have the range [-1 1]. The statement
surf(X,Y,Z,C)
allows you to see all of the data. Values of C near -1 are assigned the lowest values in the color table; values of C near +1 are assigned the highest values in the color table.To map the top half of the sphere to the highest value in the color table, enter:
caxis([-1 0])
To use only the bottom half of the color table, enter
caxis([-1 3])
Since the data in C only occupy values in the range [-1 1], the colors assigned to C come from the lower part of the color table.The command
caxis auto
resets axis scaling back to autoranging and you once again see all the colors in the mesh.
z = caxis
makes z = [-1 1].
axes, axis, colormap, get, set
The CLim and CLimMode properties of axes objects.
The ColorMap property of figure objects.
(c) Copyright 1994 by The MathWorks, Inc.