Walking Randomly

I was discussing the (relatively) new Symbolic Toolbox for MATLAB with someone yesterday and found the need to trawl through the documentation.  There is a command called mfun in the symbolic toolbox which allows you to numerically evaluate various special functions such as Dawson’s integral or the digamma function.  Let’s look at the output of  help mfun in MATLAB 2009a.  The bold highlights are mine.

help mfun
MFUN   Numeric evaluation of a special function.
MFUN(‘fun’,p1,p2,…,pk), where ‘fun’ is the name of a Maple
function and the p’s are numeric quantities corresponding to fun’s
parameters.  The last parameter specified may be a matrix. All other
parameters must be the type specified by the Maple function.
MFUN numerically evaluates ‘fun’ with the specified parameters
and returns MATLAB doubles. Any singularity in ‘fun’ is returned
as NaN.

Of course, it should be MuPAD rather than Maple these days :-)  The text in the help browser is correct though and refers to MuPAD throughout.

What’s more if you do help mfunlist in MATLAB 2009a (to list all of the functions supported by mfun) then near the end of the list you’ll get the following extract

Orthogonal Polynomials (Extended Symbolic Math Toolbox only)
T      n,x             Chebyshev of the First Kind
U      n,x             Chebyshev of the Second Kind

However, the Extended Symbolic Toolbox was discontinued from MATLAB 2008b onwards and all of the Orthogonal Polynomials mentioned in the help file are now available in new symbolic toolbox as standard.

This is no big deal (Walking Randomly probably has MANY more typos than this for example) and after a change as major as swapping the Maple toolbox for the Mupad one I guess things such as this should be expected from time to time.