C Math Library Reference

Translating MATLAB Syntax into C Syntax

This procedure demonstrates how to translate the MATLAB svd() calls into MATLAB C Math Library calls to mlfSvd(). The procedure applies to library functions in general.

In this procedure, mlfAssign(), rather than the assignment operator (=), assigns the return value from mlfSvd() to an array variable. This usage indicates that the automated memory management provided by the library is in effect.

Note that within a call to a MATLAB C Math Library function, an output argument is preceded by &; an input argument is not.

MATLAB Syntax

s = svd(X)
[U,S,V] = svd(X)
[U,S,V] = svd(X,0)

The MATLAB arguments to svd() fall into these categories:

U (or s) is a required output argument.

S and V are optional output arguments.

X is a required input argument.

0 is an optional input argument.

1. Declare input, output, and return variables as mxArray * variables. Assign values to the input variables. Initialize output and return variables to NULL.
2. Make the first output argument the return value from the function.

   mlfAssign(&s, 
   mlfAssign(&U,
   mlfAssign(&U,
   

3. Pass any additional required or optional output arguments as the first arguments to the function. Pass a NULL argument wherever an optional output argument does not apply to the particular call.

   mlfAssign(&s, mlfSvd(NULL,NULL,
   mlfAssign(&U, mlfSvd(&S,&V,
   mlfAssign(&U, mlfSvd(&S,&V,
   s = mlfSvd(NULL,NULL,
   U = mlfSvd(&S,&V,
   U = mlfSvd(&S,&V,
   

4. Pass any required or optional input arguments that apply to the C function, following the output arguments. Pass a NULL argument wherever an optional input argument does not apply to the particular call.

   mlfAssign(&s, mlfSvd(NULL,NULL,X,NULL));
   mlfAssign(&U, mlfSvd(&S,&V,X,NULL));
   mlfAssign(&U, mlfSvd(&S,&V,X,Zero));
   

Constructing a C Prototype

Function Reference