/// <summary>
/// GEneral Matrix Multiply this array
/// </summary>
/// <overloads>General Matrix Multiply for double, float, complex and fcomplex arrays</overloads>
/// <param name="A"><![CDATA[ILArray<>]]> matrix A</param>
/// <param name="B"><![CDATA[ILArray<>]]> matrix B</param>
/// <returns><![CDATA[ILArray<double>]]> new array - result of matrix multiplication</returns>
/// <remarks>Both arrays must be matrices. The matrix will be multiplied only
/// if dimensions match accordingly. Therefore B's number of rows must
/// equal A's number of columns. An Exception will be thrown otherwise.
/// The multiplication will carried out on BLAS libraries, if availiable and the
/// storage memory structure meets BLAS's requirements. If not it will be done inside .NET's
/// framework 'by hand'. This is especially true for referencing storages with
/// irregular dimensions. However, even GEMM on those reference storages linking into
/// a physical storage can (an will) be carried out via BLAS dll's, if the spacing
/// into dimensions matches the requirements of BLAS. Those are:
/// <list>
/// <item>the elements of one dimension will be adjecently layed out, and</item>
/// <item>the elements of the second dimension must be regular (evenly) spaced</item>
/// </list>
/// <para>For reference arrays where the spacing between adjecent elements do not meet the
/// requirements above, the matrix multiplication will be made without optimization and
/// therefore suffer from low performance in relation to solid arrays. See <a href="http://ilnumerics.net?site=5142">online documentation: referencing for ILNumerics.Net</a></para>
/// </remarks>
/// <exception cref="ILNumerics.Exceptions.ILArgumentSizeException">if at least one arrays is not a matrix</exception>
/// <exception cref="ILNumerics.Exceptions.ILDimensionMismatchException">if the size of both matrices do not match</exception>
public static ILArray <fcomplex> multiply(ILArray <fcomplex> A, ILArray <fcomplex> B)
{
ILArray <fcomplex> ret = null;
if (A.Dimensions.NumberOfDimensions != 2 ||
B.Dimensions.NumberOfDimensions != 2)
{
throw new ILArgumentSizeException("Matrix multiply: arguments must be 2-d.");
}
if (A.Dimensions[1] != B.Dimensions[0])
{
throw new ILDimensionMismatchException("Matrix multiply: inner matrix dimensions must match.");
}
// decide wich method to use
// test auf Regelmigkeit der Dimensionen
int spacingA0;
int spacingA1;
int spacingB0;
int spacingB1;
char transA, transB;
fcomplex [] retArr = null;
isSuitableForLapack(A, B, out spacingA0, out spacingA1, out spacingB0, out spacingB1, out transA, out transB);
if (A.m_dimensions.NumberOfElements > ILAtlasMinimumElementSize ||
B.m_dimensions.NumberOfElements > ILAtlasMinimumElementSize)
{
// do BLAS GEMM
retArr = new fcomplex [A.m_dimensions[0] * B.m_dimensions[1]];
if (((spacingA0 == 1 && spacingA1 > int.MinValue) || (spacingA1 == 1 && spacingA0 > int.MinValue)) &&
((spacingB0 == 1 && spacingB1 > int.MinValue) || (spacingB1 == 1 && spacingB0 > int.MinValue)))
{
ret = new ILArray <fcomplex> (retArr, new ILDimension(A.m_dimensions[0], B.m_dimensions[1]));
if (transA == 't')
{
spacingA1 = spacingA0;
}
if (transB == 't')
{
spacingB1 = spacingB0;
}
unsafe
{
fixed(fcomplex *ptrC = retArr)
fixed(fcomplex * pA = A.m_data)
fixed(fcomplex * pB = B.m_data)
{
fcomplex *ptrA = pA + A.getBaseIndex(0);
fcomplex *ptrB = pB + B.getBaseIndex(0);
if (transA == 't')
{
spacingA1 = spacingA0;
}
if (transB == 't')
{
spacingB1 = spacingB0;
}
Lapack.cgemm(transA, transB, A.m_dimensions[0], B.m_dimensions[1],
A.m_dimensions[1], ( fcomplex )1.0, (IntPtr)ptrA, spacingA1,
(IntPtr)ptrB, spacingB1, ( fcomplex )1.0, retArr, A.m_dimensions[0]);
}
}
return(ret);
}
}
// do GEMM by hand
retArr = new fcomplex [A.m_dimensions[0] * B.m_dimensions[1]];
ret = new ILArray <fcomplex> (retArr, A.m_dimensions[0], B.m_dimensions[1]);
unsafe {
int in2Len1 = B.m_dimensions[1];
int in1Len0 = A.m_dimensions[0];
int in1Len1 = A.m_dimensions[1];
fixed(fcomplex *ptrC = retArr)
{
fcomplex *pC = ptrC;
for (int c = 0; c < in2Len1; c++)
{
for (int r = 0; r < in1Len0; r++)
{
for (int n = 0; n < in1Len1; n++)
{
*pC += A.GetValue(r, n) * B.GetValue(n, c);
}
pC++;
}
}
}
}
return(ret);
}