UIMAGE - UIMAGESC

Display image with non-linearly spaced axis.

UIMAGE(X,Y,C) displays matrix C as an image, using the vectors X and Y to specify the X and Y coordinates. X and Y may be unevenly spaced vectors, but must be increasing. The size of C must be LENGTH(Y)*LENGTH(X). (Most probably you'll want to display C' instead of C).

Contrary to Matlab's original IMAGE function, here the vectors X and Y do not need to be linearly spaced. Whereas Matlab's IMAGE function linearly interpolates the X-axis between X(1) and X(end), ignoring all other values (idem for Y), here UIMAGE allows for X and/or Y to be unevenly spaced vectors, by locally stretching the matrix C (ie, by duplicating some elements of C) for larger X and/or Y intervals.

Use UIMAGESC to scale the data using the full colormap. The syntax for UIMAGESC(X,Y,C,...) is the same as IMAGESC(X,Y,C,...).

Typical uses:
- Plotting a spatio-temporal diagram (T,X), with unevenly spaced time intervals for T (eg, when some values are missing, or when using a non-constant sampling rate).
- Plotting a set of power spectra with frequency in log-scale.

Example:
c = randn(50,20); % Random 50x20 matrix
x = logspace(1,3,50); % log-spaced X-axis, between 10 and 1000
y = linspace(3,8,20); % lin-spaced Y-axis, between 3 and 8
uimagesc(x,y,c'); % displays the matrix