/// <summary>
/// Returns the transpose of this matrix.
/// </summary>
/// <returns>The transpose of this matrix.</returns>
public override Matrix<double> Transpose()
{
var ret = new SparseMatrix(ColumnCount, RowCount)
{
_columnIndices = new int[NonZerosCount],
_nonZeroValues = new double[NonZerosCount]
};
// Do an 'inverse' CopyTo iterate over the rows
for (var i = 0; i < _rowIndex.Length; i++)
{
// Get the begin / end index for the current row
var startIndex = _rowIndex[i];
var endIndex = i < _rowIndex.Length - 1 ? _rowIndex[i + 1] : NonZerosCount;
// Get the values for the current row
if (startIndex == endIndex)
{
// Begin and end are equal. There are no values in the row, Move to the next row
continue;
}
for (var j = startIndex; j < endIndex; j++)
{
ret.SetValueAt(_columnIndices[j], i, _nonZeroValues[j]);
}
}
return ret;
}