private void ReduceRow(int pivotIdx, Row row) { for (int j = pivotIdx + 1; j < row.Xs.Length; j++) { if (j >= Matrix.NumRows) return; var r = Matrix[j, IndexType.Row]; if (r[j] == 0) continue; row.AddMult(r, row.Xs[j] / -r[j]); LogStep(); } }