/// <summary> /// Returns a sparse sub-matrix containing the requested rows. /// </summary> /// <param name="matrix"></param> /// <param name="rowIndices">The rows to extract.</param> /// <returns>The requested sub-matrix.</returns> public static SparseMatrix FastGetRows(this SparseMatrix matrix, int[] rowIndices) { var target = new SparseMatrix(rowIndices.Length, matrix.ColumnCount); matrix.FastGetRows(rowIndices, target); return(target); }