I am trying to use your product to find the best fit parabola for data we have collected in a C++ .NET 2003 Unmanaged code program.

Below is my code:

::CoInitialize(NULL);

hr = ::CoCreateInstance(__uuidof(Matrix), NULL, CLSCTX_INPROC, __uuidof(IMatrix), (void**)&pLftMatrix);

if(FAILED(hr))

return result;

hr = ::CoCreateInstance(__uuidof(Matrix), NULL, CLSCTX_INPROC, __uuidof(IMatrix), (void**)&pRtMatrix);

if(FAILED(hr))

return result;

//Set the Left Matrix size

//Set the Right Matrix size

//Fill the matrices with data

for (i = 0; i <= nDataPts; i++)

{

pLftMatrix->Item[i][0] = 1;

pLftMatrix->Item[i][1] = zPos[i];

pLftMatrix->Item[i][2] = zPos[i] * zPos[i];

pRtMatrix->Item[i][0] = thickness[i];

}

pTLftMatrix = pLftMatrix->Transpose();

/*My program dies here.  The call pTLftMatrix->Cols causes an exception.  What am I doing wrong?  Also  How can I capture the exceptions.  I have a catch for : 

catch (_com_error& e)  But it doesn't catch it.

Below is the rest of my code.*/

errMsg.Format("TLeftMatrix Cols = %s", pTLftMatrix->Cols);

errMsg.Format("LeftMatrix Rows = %s", pLftMatrix->Rows);

if(pTLftMatrix->Cols == pLftMatrix->Rows)

{

tempPtr = pTLftMatrix->Times(&pLftMatrix);

p3X3LftMatrix = tempPtr->Clone();

}

if(pTLftMatrix->Cols == pRtMatrix->Rows)

{

tempPtr = pTLftMatrix->Times(&pRtMatrix);

p3X1RtMatrix = tempPtr->Clone();

}

pSolveMatrix = p3X3LftMatrix->SolveGauss(&p3X1RtMatrix);

result.thickness = pSolveMatrix->Item[0][0] - (pSolveMatrix->Item[1][0] * pSolveMatrix->Item[1][0] / 4 * pSolveMatrix->Item[2][0]);

result.zPos = -pSolveMatrix->Item[1][0] / 2 * pSolveMatrix->Item[2][0];

result.density = 0;

result.Successful = true;

if(pLftMatrix)

pLftMatrix->Release();

if(pRtMatrix)

pRtMatrix->Release();

Do you have more examples for using the ActiveX component with C++?

Thanks

Diane

In the "Samples\C++ Demo" folder (default install location "C:\Program Files\Matrix ActiveX Component 3.1\Samples\C++ Demo" ) we have a C++ project which demonstrates the use of MaXC with C++.

In order to set a matrix element you should use:

A->PutItem( row, col, val);

Your suggestion was helpful.  But I have already looked at that example.  It is very limited.  I set the items using SetItem(long, long, double)?

When I do a GetString(long, linedelimitors), I don't get the matrix back.

CString temp;

temp.Format("%s", A->GetString(5, ""));

Is there some help for the C++ function calls?

Cheers

Marmot

You know I am creeping along here. And I am wondering if some of my troubles are related to the program not recognizing our registered copy of the program.

pMatrix is the transpose of pMatrix2

pMatrix2 is a 10 X 3 matrix and pMatrix is a 3 X 10 matrix and pMatrix3 should be a 3 X 3 matrix.   

pMatrix3 = pMatrix->Times(&pMatrix2);

   pMatrix3->GetCols();  //This causes an exception

So what am I doing wrong?

Thanks

Marmot

I declared a IMatrixPtr tempPtr;

tempPtr = pLeftMatrix->Transpose(&pRtMatrix)

pTLftMatrix = tempPtr.Detach();

Cheers

Marmot