Histogram transformation

transformHistogram transforms a frequency histogram according to a formula specified as an argument.

[transformedHistogram,newX]=transformHistogram(originalHistogram,originalX,formula)
transformHistogram transforms the histogram stored in the 1D array 'orignalHistogram' according to the formula 'formula'.
'originalHistogram' is defined at bins stored in 'orignalX'.
The output 'transformedHistogram' contains the transformed histogram at the same bins as the originalHistogram.
The histogram is assumed to be stored according to the following principle:
f(X(i)) = frequency (X(i)<lambda<=X(i+1))
f(X(end) = frequency (lambda=X(end))
This is the principle how histc generates its output.
The best is if f(end)=0
'formula' has to be a string containing the transformation rules. The variable has to be x, e.g. 2x+3
Example: transformHistogram(starved,xscale,'x.^2')