Compiling c code to mex file

This is an inbuilt example in matlab

See the link:< http://www.mathworks.com/support/solutions/en/data/1-C61XJF/index.html?product=SL&solution=1-C61XJF>

i am getting an error while compiling c file:

mex getputvariable.c

    C:\PROGRA~1\MATLAB\R2012B\BIN\MEX.PL: Error: 'getputvariable.c' not found. 

Error using mex (line 206)
Unable to complete successfully.

What could be the problem?

[Kaustubha Govind]

Did you download the getputvariable.c file into your current folder? Is it listed when you run "ls" in the command window?

[Shyam]

oops..the filename is actually mexgetputvariable.c...so i hav to type

mex mexgetputvariable.c

pls delete this question

Answer 1

[James Tursa]

If you are just using this example as a learning exercise, fine. But the example given is not a good way to go about things in general. Getting variables by name directly from a workspace and then replacing them will be prone to errors in the long run ... it binds you to exact variable names and from looking at the calling code you cannot tell at all what variables are used & changed by the mex call. It is much better to pass in variables through the argument list prhs and pass out results via plhs than it is to use this example. And a small nit about the code itself are these two lines:

      array_ptr=mxCreateDoubleMatrix(1,1,mxREAL);   /* size of 1x1 (scalar) */
      array_ptr = mexGetVariable("base", array_name);

The first line is absolutely useless and in fact results in a memory leak since the pointer returned by the mxCreateDoubleMatrix call is wiped out on the very next line by the result of the mexGetVariable call. That first line should just be deleted.