/// <summary>
/// Performs the following operation for 0 <= i < <see cref="Order"/>, 0 <= j <= i:
/// result[i, j] = <paramref name="otherCoefficient"/> * <paramref name="otherMatrix"/>[i, j] + this[i, j].
/// The resulting matrix is written to a new <see cref="TriangularLower"/> and then returned.
/// </summary>
/// <param name="otherMatrix">A matrix with the same <see cref="Order"/> as this <see cref="TriangularLower"/>
/// instance.</param>
/// <param name="otherCoefficient">A scalar that multiplies each entry of <paramref name="otherMatrix"/>.</param>
/// <exception cref="NonMatchingDimensionsException">Thrown if <paramref name="otherMatrix"/> has different
/// <see cref="Order"/> than this instance.</exception>
public TriangularLower Axpy(TriangularLower otherMatrix, double otherCoefficient)
{
Preconditions.CheckSameMatrixDimensions(this, otherMatrix);
//TODO: Perhaps this should be done using mkl_malloc and BLAS copy.
double[] result = new double[data.Length];
Array.Copy(this.data, result, data.Length);
Blas.Daxpy(data.Length, otherCoefficient, otherMatrix.data, 0, 1, result, 0, 1);
return(new TriangularLower(result, NumRows));
}
/// <summary>
/// Performs the following operation for 0 <= i < <see cref="Order"/>, 0 <= j <= i:
/// this[i, j] = <paramref name="thisCoefficient"/> * this[i, j]
/// + <paramref name="otherCoefficient"/> * <paramref name="otherMatrix"/>[i, j].
/// The resulting matrix overwrites the entries of this <see cref="TriangularLower"/> instance.
/// </summary>
/// <param name="thisCoefficient">A scalar that multiplies each entry of this <see cref="TriangularLower"/>.</param>
/// <param name="otherMatrix">A matrix with the same <see cref="Order"/> as this <see cref="TriangularLower"/>
/// instance.</param>
/// <param name="otherCoefficient">A scalar that multiplies each entry of <paramref name="otherMatrix"/>.</param>
/// <exception cref="NonMatchingDimensionsException">Thrown if <paramref name="otherMatrix"/> has different
/// <see cref="Order"/> than this instance.</exception>
public void LinearCombinationIntoThis(double thisCoefficient, TriangularLower otherMatrix, double otherCoefficient)
{
Preconditions.CheckSameMatrixDimensions(this, otherMatrix);
if (thisCoefficient == 1.0)
{
Blas.Daxpy(data.Length, otherCoefficient, otherMatrix.data, 0, 1, this.data, 0, 1);
}
else
{
BlasExtensions.Daxpby(data.Length, otherCoefficient, otherMatrix.data, 0, 1, thisCoefficient, this.data, 0, 1);
}
}
/// <summary>
/// Performs the following operation for 0 <= i < <see cref="Order"/>, 0 <= j <= i:
/// result[i, j] = <paramref name="thisCoefficient"/> * this[i, j]
/// + <paramref name="otherCoefficient"/> * <paramref name="otherMatrix"/>[i, j].
/// The resulting matrix is written to a new <see cref="TriangularLower"/> and then returned.
/// </summary>
/// <param name="thisCoefficient">A scalar that multiplies each entry of this <see cref="TriangularLower"/>.</param>
/// <param name="otherMatrix">A matrix with the same <see cref="Order"/> as this <see cref="TriangularLower"/>
/// instance.</param>
/// <param name="otherCoefficient">A scalar that multiplies each entry of <paramref name="otherMatrix"/>.</param>
/// <exception cref="NonMatchingDimensionsException">Thrown if <paramref name="otherMatrix"/> has different
/// <see cref="Order"/> than this instance.</exception>
public TriangularLower LinearCombination(double thisCoefficient, TriangularLower otherMatrix, double otherCoefficient)
{
Preconditions.CheckSameMatrixDimensions(this, otherMatrix);
//TODO: Perhaps this should be done using mkl_malloc and BLAS copy.
double[] result = new double[data.Length];
if (thisCoefficient == 1.0)
{
Array.Copy(this.data, result, data.Length);
Blas.Daxpy(data.Length, otherCoefficient, otherMatrix.data, 0, 1, result, 0, 1);
}
else if (otherCoefficient == 1.0)
{
Array.Copy(otherMatrix.data, result, data.Length);
Blas.Daxpy(data.Length, thisCoefficient, this.data, 0, 1, result, 0, 1);
}
else
{
Array.Copy(this.data, result, data.Length);
BlasExtensions.Daxpby(data.Length, otherCoefficient, otherMatrix.data, 0, 1, thisCoefficient, result, 0, 1);
}
return(new TriangularLower(result, NumRows));
}
/// <summary>
/// Performs the following operation for 0 <= i < <see cref="Order"/>, 0 <= j <= i:
/// this[i, j] = <paramref name="otherCoefficient"/> * <paramref name="otherMatrix"/>[i, j] + this[i, j].
/// The resulting matrix overwrites the entries of this <see cref="TriangularLower"/> instance.
/// </summary>
/// <param name="otherMatrix">A matrix with the same <see cref="Order"/> as this <see cref="TriangularLower"/>
/// instance.</param>
/// <param name="otherCoefficient">A scalar that multiplies each entry of <paramref name="otherMatrix"/>.</param>
/// <exception cref="NonMatchingDimensionsException">Thrown if <paramref name="otherMatrix"/> has different
/// <see cref="Order"/> than this instance.</exception>
public void AxpyIntoThis(TriangularLower otherMatrix, double otherCoefficient)
{
Preconditions.CheckSameMatrixDimensions(this, otherMatrix);
Blas.Daxpy(data.Length, otherCoefficient, otherMatrix.data, 0, 1, this.data, 0, 1);
}