Add graph references

2026-06-28 13:49:01 +01:00
parent 0a9807e448
commit a11edf0c53
2578 changed files with 868045 additions and 0 deletions
@@ -0,0 +1,75 @@
+/*
+   igraph library.
+   Copyright (C) 2024  The igraph development team <igraph@igraph.org>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+#include <igraph.h>
+
+#include "../unit/test_utilities.h"
+
+/* Regression test for https://github.com/igraph/igraph/issues/1814 */
+
+void test_igraph_to_undirected(igraph_to_undirected_t mode) {
+    igraph_t g;
+    igraph_attribute_combination_t comb;
+
+    igraph_small(&g, 4, IGRAPH_DIRECTED,
+                 0,1, 0,1, 1,0,
+                 1,1, 1,1,
+                 -1);
+
+    SETEAN(&g, "weight", 0, 1);
+    SETEAN(&g, "weight", 1, 2);
+    SETEAN(&g, "weight", 2, 3);
+    SETEAN(&g, "weight", 3, 4);
+    SETEAN(&g, "weight", 4, 2);
+
+    igraph_attribute_combination(
+        &comb, "weight", IGRAPH_ATTRIBUTE_COMBINE_SUM,
+        IGRAPH_NO_MORE_ATTRIBUTES
+    );
+    igraph_to_undirected(&g, mode, &comb);
+    igraph_attribute_combination_destroy(&comb);
+
+    igraph_write_graph_gml(&g, stdout, IGRAPH_WRITE_GML_DEFAULT_SW, 0, "");
+
+    igraph_destroy(&g);
+
+    VERIFY_FINALLY_STACK();
+}
+
+int main(void) {
+    igraph_set_attribute_table(&igraph_cattribute_table);
+
+    printf("to_undirected(COLLAPSE)\n");
+    printf("=======================\n\n");
+    test_igraph_to_undirected(IGRAPH_TO_UNDIRECTED_COLLAPSE);
+    printf("\n");
+
+    printf("to_undirected(MUTUAL)\n");
+    printf("=====================\n\n");
+    test_igraph_to_undirected(IGRAPH_TO_UNDIRECTED_MUTUAL);
+    printf("\n");
+
+    printf("to_undirected(EACH)\n");
+    printf("===================\n\n");
+    test_igraph_to_undirected(IGRAPH_TO_UNDIRECTED_EACH);
+    printf("\n");
+
+    VERIFY_FINALLY_STACK();
+
+    return 0;
+}