Customizable Heat Maps

********** Updated for 2014b *********
HEATMAP displays a matrix as an image whose color intensities reflect the magnitude of its values. In addition, it enables you to specify the following properties:
* X- and Y-axes tick labels:
Display the row/column indices or any other numeric or text labels. X-axis tick labels can even be rotated.
* Text labels:
Overlay the heatmap image with formatted text labels. The text labels can be derived from the original numeric matrix or a different matrix or cell array for displaying another dimension of data. You can control the font size and font color of the labels. The labels update automatically with zooming, panning or resizing the figure.

* Custom color maps:
Use MATLAB's default color maps or specify your own. The function provides two additional color maps - "money" (shown in the example image) and "red" (a color map of red color intensities). Specify Linear or Logarithmic color maps and the number of color levels. You can even use different color maps for different heat maps within a figure.

* Other configurable parameters such as grid lines, color bars.

For detailed examples, see the associated document heatmap_examples.m

NOTE: If using rotated tick labels, HEATMAP will resize the axes to make room for the tick labels. When overwriting existing heatmap plots with a new heatmap, use CLF to first clear the figure. See heatmap_examples for an illustration.