/// <summary>
/// See <see cref="IMatrixView.MultiplyRight(IMatrixView, bool, bool)"/>.
/// </summary>
public Matrix MultiplyRight(IMatrixView other, bool transposeThis = false, bool transposeOther = false)
{
// TODO: Throwing exceptions when csc is on the left seems attractive.
if (transposeOther)
{
if (transposeThis)
{
Preconditions.CheckMultiplicationDimensions(this.NumRows, other.NumColumns);
var result = Matrix.CreateZero(this.NumColumns, other.NumRows);
CsrMultiplications.CsrTimesMatrixTrans(this.NumColumns, values, colOffsets, rowIndices, other, result);
return(result);
}
else
{
Preconditions.CheckMultiplicationDimensions(this.NumColumns, other.NumColumns);
var result = Matrix.CreateZero(this.NumRows, other.NumRows);
CsrMultiplications.CsrTransTimesMatrixTrans(this.NumColumns, values, colOffsets, rowIndices, other, result);
return(result);
}
}
else
{
//TODO: perhaps I can use the left multiplications if the other matrix is also transposed
if (other is Matrix dense)
{
return(MultiplyRight(dense, transposeThis));
}
if (transposeThis)
{
Preconditions.CheckMultiplicationDimensions(this.NumRows, other.NumRows);
var result = Matrix.CreateZero(this.NumColumns, other.NumColumns);
CsrMultiplications.CsrTimesMatrix(this.NumColumns, values, colOffsets, rowIndices, other, result);
return(result);
}
else
{
Preconditions.CheckMultiplicationDimensions(this.NumColumns, other.NumRows);
var result = Matrix.CreateZero(this.NumRows, other.NumColumns);
CsrMultiplications.CsrTransTimesMatrix(this.NumColumns, values, colOffsets, rowIndices, other, result);
return(result);
}
}
}
/// <summary>
/// See <see cref="IMatrixView.MultiplyIntoResult(IVectorView, IVector, bool)"/>.
/// </summary>
public void MultiplyIntoResult(IVectorView lhsVector, IVector rhsVector, bool transposeThis = false)
{
if ((lhsVector is Vector lhsDense) && (rhsVector is Vector rhsDense))
{
MultiplyIntoResult(lhsDense, rhsDense, transposeThis);
}
if (transposeThis)
{
Preconditions.CheckMultiplicationDimensions(NumRows, lhsVector.Length);
Preconditions.CheckSystemSolutionDimensions(NumColumns, rhsVector.Length);
CsrMultiplications.CsrTimesVector(NumColumns, values, colOffsets, rowIndices, lhsVector, rhsVector);
}
else
{
Preconditions.CheckMultiplicationDimensions(NumColumns, lhsVector.Length);
Preconditions.CheckSystemSolutionDimensions(NumRows, rhsVector.Length);
CsrMultiplications.CsrTransTimesVector(NumColumns, values, colOffsets, rowIndices, lhsVector, rhsVector);
}
}
/// <summary>
/// See <see cref="IMatrixView.Multiply(IVectorView, bool)"/>.
/// </summary>
public IVector Multiply(IVectorView vector, bool transposeThis = false)
{
if (vector is Vector dense)
{
return(Multiply(dense, transposeThis));
}
if (transposeThis)
{
var result = new double[NumColumns];
Preconditions.CheckMultiplicationDimensions(NumRows, vector.Length);
CsrMultiplications.CsrTimesVector(NumColumns, values, colOffsets, rowIndices, vector, result);
return(Vector.CreateFromArray(result, false));
}
else
{
var result = new double[NumRows];
Preconditions.CheckMultiplicationDimensions(NumColumns, vector.Length);
CsrMultiplications.CsrTransTimesVector(NumColumns, values, colOffsets, rowIndices, vector, result);
return(Vector.CreateFromArray(result, false));
}
}
/// <summary>
/// See <see cref="IMatrixView.MultiplyLeft(IMatrixView, bool, bool)"/>.
/// </summary>
public Matrix MultiplyLeft(IMatrixView other, bool transposeThis = false, bool transposeOther = false)
{
//TODO: To use BLAS for this too, we must accept row major matrices as output.
if (transposeOther)
{
if (transposeThis)
{
Preconditions.CheckMultiplicationDimensions(other.NumRows, this.NumColumns);
var result = Matrix.CreateZero(other.NumColumns, this.NumRows);
CsrMultiplications.MatrixTransTimesCsr(this.NumColumns, values, colOffsets, rowIndices, other, result);
return(result);
}
else
{
Preconditions.CheckMultiplicationDimensions(other.NumRows, this.NumRows);
var result = Matrix.CreateZero(other.NumColumns, this.NumColumns);
CsrMultiplications.MatrixTransTimesCsrTrans(this.NumColumns, values, colOffsets, rowIndices, other, result);
return(result);
}
}
else
{
if (transposeThis)
{
Preconditions.CheckMultiplicationDimensions(other.NumColumns, this.NumColumns);
var result = Matrix.CreateZero(other.NumRows, this.NumRows);
CsrMultiplications.MatrixTimesCsr(this.NumColumns, values, colOffsets, rowIndices, other, result);
return(result);
}
else
{
Preconditions.CheckMultiplicationDimensions(other.NumColumns, this.NumRows);
var result = Matrix.CreateZero(other.NumRows, this.NumColumns);
CsrMultiplications.MatrixTimesCsrTrans(this.NumColumns, values, colOffsets, rowIndices, other, result);
return(result);
}
}
}
