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From: Aaron Robinson on 23 Jul 2010 13:21
I am trying to create a method for accessing a C# API from matlab. Currently, I am trying to solve the problem by creating a COM server as described by this post: http://www.mathworks.com/matlabcentral/fileexchange/16549-using-c-functions-and-forms-in-matlab

Everything "seems" to work nice except for calling this C# function:
bool GetSpectrum(int spectraID, int scanNum, ref double[] mz, ref float[] intensities);

In order to give C# the proper pointers for this operation, I have tried a number of solutions.

1st attempt:
mzArray = double(zeros(100, 1));
intensityArray = single(zeros(100, 1));
feature('COM_PassSafeArrayByRef', 1);
feature('COM_SafeArraySingleDim', 1);
ScanNum = 1;
bool = reader.GetSpectrum_2(1, ScanNum, mzArray, intensityArray);

Result: This will execute but once the method has returned, it has not changed the Arrays which should be getting resized and populated.

2nd attempt:
mzArray = libpointer('doublePtr', double(zeros(1000, 1)));
intensityArray = libpointer('singlePtr', single(zeros(1000, 1)));
feature('COM_SafeArraySingleDim', 1);
bool = reader.GetSpectrum_2(1, ScanNum, mzArray, intensityArray);

Result: This will cause a segmentation violation.

I have a few other ways but everything else error ed out at the GetSpectrum_2 call because of invalid arguments. This leads me to believe that the 2nd attempt is on the right track but I am still having memory management problems. The arrays which are being returned should have between (1000-10000) values.

My Configuration:
MATLAB Version: 7.10.0.499 (R2010a)
MATLAB License: 208967
Operating System: Microsoft Windows XP
Window System: Version 5.1 (Build 2600: Service Pack 3)
Processor ID: x86 Family 15 Model 4 Stepping 3, GenuineIntel
Virtual Machine: Java 1.6.0_12-b04 with Sun Microsystems Inc. Java HotSpot(TM) Client VM mixed mode
Default Encoding: windows-1252

I have the rest of the crash dump if anyone is interested.

Thanks,
-Aaron
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