GETCLIM: Suggest appropriate values for colormap limits

getclim determines threshold values such that 2% (by default) of
values at the top and bottom of the data range will be mapped
to the extremes of the colormap.

For datasets with a few outliers that influence the range, getclim
is superior to the default behaviour of using the min and max
of the dataset.

Usage: threshVals = getclim(imdata, dataFraction)

imdata: numeric array representing an image to be displayed
dataFraction: fraction of voxels to clip at each end (default 0.02)

threshVals: column vector of values to use for clims in imshow

Example:
I = peaks(200);
min(I(:)), max(I(:)) % -6.5487, 8.1059
threshVals = getclim(I) % -4.2936, 5.8228
I2 = I;
I2(153,106) = 3*I(153,106);
min(I2(:)), max(I2(:)) % -6.5487, 23.5936
threshVals = getclim(I2) % -4.2936, 5.8228
figure
subplot(2,2,1), imshow(I, []), title('I')
subplot(2,2,2), imshow(I, threshVals), title('I+getclim')
subplot(2,2,3), imshow(I2, []), title('I2')
subplot(2,2,4), imshow(I2, threshVals), title('I2+getclim')

See also STRECHLIM, IMADJUST