/**
* Checks to see all the elements in the matrix are zeros
*
* @param m A matrix. Not modified.
* @return True if all elements are zeros or false if not
*/
public static bool isZeros(ZMatrixD1 m, double tol)
{
int length = m.getNumElements() * 2;
for (int i = 0; i < length; i++)
{
if (Math.Abs(m.data[i]) > tol)
{
return(false);
}
}
return(true);
}
/**
* <p>
* Performs an in-place element by element scalar multiplication.<br>
* <br>
* a<sub>ij</sub> = α*a<sub>ij</sub>
* </p>
*
* @param a The matrix that is to be scaled. Modified.
* @param alphaReal real component of scale factor
* @param alphaImag imaginary component of scale factor
*/
public static void scale(double alphaReal, double alphaImag, ZMatrixD1 a)
{
// on very small matrices (2 by 2) the call to getNumElements() can slow it down
// slightly compared to other libraries since it involves an extra multiplication.
int size = a.getNumElements() * 2;
for (int i = 0; i < size; i += 2)
{
double real = a.data[i];
double imag = a.data[i + 1];
a.data[i] = real * alphaReal - imag * alphaImag;
a.data[i + 1] = real * alphaImag + imag * alphaReal;
}
}
/**
* <p>
* Checks to see if the two matrices are the negative of each other:<br>
* <br>
* a<sub>ij</sub> = -b<sub>ij</sub>
* </p>
*
* @param a First matrix. Not modified.
* @param b Second matrix. Not modified.
* @param tol Numerical tolerance.
* @return True if they are the negative of each other within tolerance.
*/
public static bool isNegative(ZMatrixD1 a, ZMatrixD1 b, double tol)
{
if (a.numRows != b.numRows || a.numCols != b.numCols)
{
throw new ArgumentException("Matrix dimensions must match");
}
int length = a.getNumElements() * 2;
for (int i = 0; i < length; i++)
{
if (!(Math.Abs(a.data[i] + b.data[i]) <= tol))
{
return(false);
}
}
return(true);
}