Add MatDiag::get_rows()/get_cols() (random rows specified by indices).

The return type is MatSparse because unordered rows/cols don't remain a diagonal matrix.

misc/test/src/C++/test_MatDiag.cpp.in

@@ -86,6 +86,14 @@ int main()
 	cout << "getrows(2,5)" << endl;
 	MatGeneric<FPP,Cpu>* rows = diagMat.get_rows(2,5);
 	display_all_elts(*dynamic_cast<MatDiag<FPP>*>(rows));
+	cout << "get_rows unordered 2, 3, 8" << endl;
+	faust_unsigned_int rids[3] = {2, 3, 8};
+	MatGeneric<FPP,Cpu>* sprows = diagMat.get_rows(rids, 3);
+	display_all_elts(*dynamic_cast<Faust::MatSparse<FPP,Cpu>*>(sprows));
+	cout << "get_cols unordered 2, 3, 8" << endl;
+	faust_unsigned_int cids[3] = {2, 3, 8};
+	MatGeneric<FPP,Cpu>* spcols = diagMat.get_cols(cids, 3);
+	display_all_elts(*dynamic_cast<Faust::MatSparse<FPP,Cpu>*>(spcols));
 	cout << "end of test_MatDiag" << endl;
 	return EXIT_SUCCESS;
 }

src/faust_linear_operator/CPU/faust_MatDiag.hpp

@@ -165,15 +165,12 @@ MatGeneric<FPP,Cpu>* MatDiag<FPP>::get_rows(faust_unsigned_int row_id_start, fau
 template<typename FPP>
 MatGeneric<FPP,Cpu>* MatDiag<FPP>::get_cols(faust_unsigned_int* col_ids, faust_unsigned_int num_cols) const
 {
-	//TODO
-	return nullptr;
-
+	return MatSparse<FPP,Cpu>(*this).get_cols(col_ids, num_cols);
 }
 
 template<typename FPP>
 MatGeneric<FPP,Cpu>* MatDiag<FPP>::get_rows(faust_unsigned_int* row_ids, faust_unsigned_int num_rows) const
 {
-	//TODO
-	return nullptr;
+	return MatSparse<FPP,Cpu>(*this).get_rows(row_ids, num_rows);
 }