erf, gamma etc

[Ted Harding]

Hi All,
The functions erf, erfc, gamma, lgamma are (as has been pointed out
already by Hans-Ulrich Menzebach for the gamma) "not available on this
system" in Octave-1.1.1; Vinayak Dutt has commented that

>I was looking through the source code of octave when I found that in the file
>mappers.cc which matches the octave function to corresponding c or fortran
>code, the gamma and lgamma functions do not still use the slatec library
>fortran codes for gamma/lgamma functions if the system does not have prebuilt
>gamma/lgamma function. the mapper just return undefined function error
>for these functions. Seems John Eaton is still working on adding these slatec
>function in some coming release of Octave.

It is not a severe task to write m-files to compute these, and this I
would do since a lot of my work depends on them, especially on erf. However,
I do not want to re-write all my many m-files which call these, giving them
different names, since because their "stubs" are builtin any attempt to
call them gives the above "non-available" message, while at the same time
any attempt to re-define them results in "error: can't redefine read-only
function".

Is there a work-round, please? (Not counting what I'm doing at present
when these are needed, which is "ln -s octave-1.0 octave"!). A pity,
because 1.1.1 is in many ways a good improvement on 1.0.

Best wishes to all,
Ted.                                     (address@hidden)