public static double Nrm2(MatrixExpression a)
{
var i = a.Evaluate();
var r = Blas.nrm2(i.Length, i.Array, 0, 1);
if (a is not MatrixInput)
{
i.Dispose();
}
return(r);
}
public static (matrix, matrix) Modf(MatrixExpression a)
{
var tru = a.Evaluate();
if (a is MatrixInput)
{
tru = Copy(tru);
}
var rem = new matrix(tru.Rows, tru.Cols);
Vml.Modf(tru.Length, tru.Array, tru.Array, rem.Array);
return(tru, rem);
}
public static (matrix, matrix) SinCos(MatrixExpression a)
{
var sin = a.Evaluate();
if (a is MatrixInput)
{
sin = Copy(sin);
}
var cos = new matrix(sin.Rows, sin.Cols);
Vml.SinCos(sin.Length, sin.Array, sin.Array, cos.Array);
return(sin, cos);
}
public static (int, int) Iamin(MatrixExpression a)
{
var i = a.Evaluate();
int r = Blas.iamin(i.Length, i.Array, 0, 1);
if (a is not MatrixInput)
{
i.Dispose();
}
int col = Math.DivRem(r, i.Rows, out int row);
return(row, col);
}
public static (matrix, vector) Eigens(MatrixExpression a)
{
var v = a.Evaluate();
if (v.Rows != v.Cols)
{
ThrowHelper.ThrowIncorrectDimensionsForOperation();
}
if (a is MatrixInput)
{
v = Copy(v);
}
var w = new vector(v.Rows);
ThrowHelper.Check(Lapack.syev(Layout.ColMajor, 'V', UpLoChar.Lower, v.Rows, v.Array, v.Rows, w.Array));
return(v, w);
}
public static double Det(MatrixExpression a)
{
var m = a.Evaluate();
if (a is MatrixInput)
{
m = Copy(m);
}
var ipiv = Pool.Int.Rent(m.Rows);
ThrowHelper.Check(Lapack.getrf(Layout.ColMajor, m.Rows, m.Rows, m.Array, m.Rows, ipiv));
Pool.Int.Return(ipiv);
double r = m[0, 0];
for (int i = 1; i < m.Rows; i++)
{
r *= m[i, i];
}
m.Dispose();
return(-r);
}
