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mexPutVariable (C)

Array from MEX function into specified workspace

C Syntax

#include "mex.h"
int mexPutVariable(const char *workspace, const char *varname, 
  const mxArray *pm);



To write MEX functions using modern C++ features and the MATLAB Data API for C++, see Write C++ Functions Callable from MATLAB (MEX Files).

Call mexPutVariable to copy the mxArray, at pointer pm, from your MEX function into the specified workspace. MATLAB® assigns varname to the mxArray copied in the workspace.

mexPutVariable makes the array accessible to other entities, such as MATLAB, user-defined functions, or other MEX functions.

If a variable of the same name exists in the specified workspace, mexPutVariable overwrites the previous contents of the variable with the contents of the new mxArray. For example, suppose the MATLAB workspace defines variable Peaches as:

1     2     3     4

and you call mexPutVariable to copy Peaches into the same workspace:

mexPutVariable("base", "Peaches", pm)

The value passed by mexPutVariable replaces the old value of Peaches.

Input Arguments

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Scope of the array to copy, specified as const char*. The possible values are:


Copy mxArray to the base workspace.


Copy mxArray to the caller workspace.


Copy mxArray to the list of global variables.

Name of mxArray in the workspace, specified as const char*.

Do not use MATLAB function names for variable names. Common variable names that conflict with function names include i, j, mode, char, size, or path. To determine whether a particular name is associated with a MATLAB function, use the which function.

Pointer to the mxArray.

Output Arguments

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Status, returned as 0 on success. Returns 1 on failure. A possible cause of failure is that pm is NULL.


See these examples in matlabroot/extern/examples/mex:

Version History

Introduced before R2006a