mxMakeArrayComplex (C) - Convert real mxArray to complex, preserving real

        data - MATLAB ([original](https://www.mathworks.com/help/matlab/apiref/mxmakearraycomplex.html)) ([raw](?raw))

Convert real mxArray to complex, preserving real data

C Syntax

#include "matrix.h" int mxMakeArrayComplex(mxArray *pa);

Description

Use mxMakeArrayComplex to convert a realmxArray to a complex mxArray. The real part of the updated array contains the real data from the original array.

If pa is empty, then the function returns a complex emptymxArray.

If pa is complex, then the function does nothing.

Input Arguments

expand all

Pointer to a numeric mxArray array.

Output Arguments

expand all

Function status, returned as int. If successful, then the function returns 1.

Returns 0 if unsuccessful. The function is unsuccessful if pa is NULL, nonnumeric, or read-only.

Examples

Suppose that your application processes complex data and you create complexmxArrays to handle the data. If you pass a complex array containing only real data to a MATLAB® function, then the returned value is a real array. For example, call the MATLABsqrt function with the following input.

a =

2.0000 + 0.0000i 4.0000 + 0.0000i

Although the input argument is complex, the data is real-only, and the output of the function is no longer complex.

To maintain the complexity of the data, use themxMakeArrayComplex function to wrap the result. To build the MEX file complexFnc.c:

void mexFunction( int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[] ) { mxArray *rhs[1], *lhs[1];

/* check for the proper number of arguments */
if(nrhs != 1) {
    mexErrMsgIdAndTxt("MATLAB:complexFnc:checkrhs","1 input required.");
}

if(nlhs > 1) {
    mexErrMsgIdAndTxt("MATLAB:complexFnc:checklhs","Too many output arguments.");
}

#if MX_HAS_INTERLEAVED_COMPLEX

/* get the square root */
rhs[0] = mxDuplicateArray(prhs[0]);
mexCallMATLAB(1, lhs, 1, rhs, "sqrt");
if(!mxIsComplex(lhs[0])) {
    /* preserve complexity of data */
    mxMakeArrayComplex(lhs[0]);
}

plhs[0] = mxDuplicateArray(lhs[0]);

#endif }

Version History

Introduced in R2018a