TSubMat sub(const TMat &m, Int nrows, Int ncols)
{
Assert(ncols > 0 && nrows > 0 && nrows <= m.Rows() && ncols <= m.Cols(),
"(sub(Mat)) illegal subset of matrix");
TSubMat result(nrows, ncols, m.Cols(), m.Ref());
return(result);
}
TSubMat sub(const TMat &m, Int top, Int left, Int height, Int width)
{
Assert(left >= 0 && width > 0 && left + width <= m.Cols(), "(sub(Mat)) illegal subset of matrix");
Assert(top >= 0 && height > 0 && top + height <= m.Rows(), "(sub(Mat)) illegal subset of matrix");
TSubMat result(height, width, m.Cols(), m.Ref() + top * m.Cols() + left);
return(result);
}
TVec operator * (const TVec &v, const TMat &m) // v * m
{
Assert(v.Elts() == m.Rows(), "(Mat::v*m) vector/matrix sizes don't match");
TMVec temp(m.Cols(), vl_zero); // accumulate in high precision
TVec result(m.Cols()); // return low precision.
Int i;
for (i = 0; i < m.Rows(); i++)
temp += m[i] * v[i];
for (i = 0; i < temp.Elts(); i++)
result[i] = temp[i];
return(result);
}
TSparseMat::TSparseMat(const TMat &m) : row(0)
{
Int i;
SetSize(m.Rows(), m.Cols());
for (i = 0; i < rows; i++)
row[i] = m[i];
}
TMSubVec diag(const TMat &m, Int diagNum)
{
CheckRange(diagNum, 1 - m.Rows(), m.Cols(), "(row(Mat)) illegal row index");
if (diagNum == 0)
return(TMSubVec(Min(m.Rows(), m.Cols()), m.Cols() + 1, m.Ref()));
else if (diagNum < 0)
return(TMSubVec(Min(m.Rows() + diagNum, m.Cols()), m.Cols() + 1,
m.Ref() - diagNum * m.Cols()));
else
return(TMSubVec(Min(m.Cols() - diagNum, m.Rows()), m.Cols() + 1,
m.Ref() + diagNum));
}
TVec operator * (const TMat &m, const TVec &v)
{
Assert(m.Cols() == v.Elts(), "(Mat::*v) matrix and vector sizes don't match");
Int i;
TVec result(m.Rows());
for (i = 0; i < m.Rows(); i++)
result[i] = dot(m[i], v);
return(result);
}
TMSubVec row(const TMat &m, Int i)
{
CheckRange(i, 0, m.Rows(), "(row(Mat)) illegal row index");
return(TMSubVec(m.Cols(), 1, m[i].Ref()));
}
TMSubVec col(const TMat &m, Int i)
{
CheckRange(i, 0, m.Cols(), "(col(Mat)) illegal column index");
return(TMSubVec(m.Rows(), m.Cols(), m.Ref() + i));
}
