diagonalmatrix.d

import matrix;

import openmethods;
mixin(registerMethods);

class DiagonalMatrix : Matrix
{
	@property int rows() const { return cast(int) elems.length; }
	@property int cols() const { return cast(int) elems.length; }
	@property double at(int i, int j) const { return i == j ? elems[i] : 0; }

	double[] elems;

	this()
	{
	}

	this(double[] elems)
	{
		this.elems = elems.dup;
	}
}

@method
DiagonalMatrix _plus(DiagonalMatrix a, DiagonalMatrix b)
{
	assert(a.elems.length == b.elems.length);
	auto result = new DiagonalMatrix;
	result.elems.length = a.elems.length;
	result.elems[] = a.elems[] + b.elems[];
	return result;
}

@method("times")
DiagonalMatrix doubleTimesDiagonal(double a, DiagonalMatrix b) {
	auto result = new DiagonalMatrix;
	result.elems.length = b.elems.length;
	result.elems[] = a * b.elems[];
	return result;
}

@method("times")
DiagonalMatrix DiagonalTimesDouble(DiagonalMatrix a, double b) {
	return doubleTimesDiagonal(b, a);
}