mxSetPi (C)

(Not recommended) Set imaginary data elements in mxDOUBLE_CLASS array

mxSetPi is not available in the interleaved complex API. Use mxSetComplexDoubles instead. For more information, see Version History.

C Syntax

#include "matrix.h"
void mxSetPi(mxArray *pm, double *pi);

Description

Use mxSetPi to set the imaginary data of the specified mxArray.

Most mxCreate* functions optionally allocate heap space to hold imaginary data. If you allocate heap space when calling an mxCreate* function, then do not use mxSetPi to initialize the imaginary elements of the array. Instead, call this function to replace existing values with new values. Examples of allocating heap space include setting the ComplexFlag to mxCOMPLEX or setting pi to a non-NULL value.

The mxSetPi function does not free any memory allocated for existing data that it displaces. To free existing memory, call mxFree on the pointer returned by mxGetPi.

Input Arguments

pm — Pointer to MATLAB^® array

mxArray *

Pointer to a MATLAB array of type mxDOUBLE_CLASS, specified as mxArray *.

pi — Pointer to data array

double *

Pointer to the first mxDouble element of the imaginary part of the data array within an mxArray, specified as double *. Each element in the array contains the imaginary component of a value.

The array must be in dynamic memory. Call mxCalloc to allocate this memory. Do not use the ANSI^® C calloc function, which can cause memory alignment issues leading to program termination. If pi points to static memory, then memory leaks and other memory errors can result.

Version History

Introduced before R2006a

R2018a: Do not use separate complex API

Use the mxSetComplexDoubles function in the interleaved complex API instead of mxSetPr and mxSetPi. This function verifies that the input array is complex and of type mxDOUBLE_CLASS.

MathWorks recommends that you create MEX files and update existing MEX files to use the typed, data-access functions in the interleaved complex API. For more information, see:

• Typed Data Access in C MEX Files

• MATLAB Support for Interleaved Complex API in MEX Functions

• Upgrade MEX Files to Use Interleaved Complex API

• Example arrayFillSetPr.c

To build the MEX file, call mex with the -R2018a option.

R2018a: Error building mxSetPi with interleaved complex API

The mxSetPi function is only available in the separate complex API. To build myMexFile.c using this function, type:

mex -R2017b myMexFile.c

Existing MEX files built with this function continue to run.