inplace_

Matlab versions of the c/c++ operators +=, *= (plus circshift) working in-place and avoiding unneces

Description

To date I implemented a few functions I needed, i.e. some C-like operators and circshift:
  inplace(x, y, '+=');
  inplace(x, y, '.*=');
  inplace(x, ns, 'circshift');
that do not allocate memory and compared to the matlab equivalent
  x = x + y;
  x = x .* y;
  x = circshift(x, ns);
are (when working with arrays above 300-400 MB) much faster (tenths of second instead of a few minutes) because the pc does not start swapping to the disk.
The matlab equivalents are currently optimized (performed in-place) only in M-code, but not at the command line.
See http://blogs.mathworks.com/loren/?p=36 for a discussion about it.
IMPORTANT: this piece of code infringes the recommendation that mex files should not overwrite input data.

• MATLAB release: MATLAB 7.0.4 (R14SP2)
• Other requirements: To compile it you need to configure the C compiler in matlab. Otherwise you can try the compiled versions (inplace_.dll and inplace_.mexglx).

[Joaquim Luis]

Luca, the cvlib_mex submission already did dat with further advantages:
1. It works with all data types (except uin32) and not only with doubles.
2. With pentiums it uses the Matlab MKS library to do matrice operations