MATLAB: How to change datatype of libpointer

libpointer;datatype;calllib;shared lib;MATLAB

Hi , I am trying to use Matlab and shared library.

If I have a C function which is like below

void * foo(int n);

It's just like that we get a void type pointer containing n int data , returned from foo .

In C , we can change void type to int or double easily.

But how to change type in Matlab ?

I tried

pointer = calllib(lib,'foo',1000);
pointer.datatype = 'uint16Ptr';  %Changing the 'DataType' property of lib.pointer is not allowed.

Best Answer

setdatatype(pointer, 'uint16Ptr', n);  %assuming the pointer points to an array of n uint16

should work.

Related Solutions

MATLAB: Converting mxArrays to libpointer in MATLAB block

I would recommend that you move all creation/extraction of libpointers also inside an extrinsic function, and have only builtin (MATLAB) types at the interface, so that you can pre-define them appropriately in your top-level function.

MATLAB: Advancing a structure pointer in calllib – shared library

If you are using R2009a or later then you can increment your pointer like so:

    nextDataBlock=sblptr+1;
    nextDataBlock=nextDataBlock+1;
    % or
    dataBlockN=sblptr+N;

I suggest minimizing use of the same pointer variables on both sides of a calllib statement. When libpointer objects are used as inputs they are modified in place and no output argument is needed. Libpointer objects should not be needed for the arguments to fwifc_read that are single pointers for those that may be modified by the call the return value can be examined.

Best Answer

Related Solutions

MATLAB: Converting mxArrays to libpointer in MATLAB block

MATLAB: Advancing a structure pointer in calllib – shared library

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