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 +1,100 @@
+/*
+   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 "bench.h"
+
+/*
+ * Benchmark creating graphs from dense adjacency matrices.
+ *
+ * When there are a small number of non-zero elements (low mean degree),
+ * iterating through the matrix dominates the timing. When there are
+ * many non-zero elements, creating the graphfrom its edge list dominates.
+ */
+
+void adjacency(const igraph_matrix_t *adjmatrix, igraph_adjacency_t mode, igraph_loops_t loops) {
+    igraph_t g;
+    igraph_adjacency(&g, adjmatrix, mode, loops);
+    igraph_destroy(&g);
+}
+
+void weighted_adjacency(const igraph_matrix_t *adjmatrix, igraph_adjacency_t mode, igraph_vector_t *weights, igraph_loops_t loops) {
+    igraph_t g;
+    igraph_weighted_adjacency(&g, adjmatrix, mode, weights, loops);
+    igraph_destroy(&g);
+}
+
+void run_bench(igraph_int_t vcount, igraph_int_t meandeg, igraph_int_t rep) {
+    igraph_t g;
+    igraph_matrix_t mat;
+    igraph_vector_t weights;
+    char msg[128];
+    igraph_adjacency_t types[] = {
+        IGRAPH_ADJ_DIRECTED,
+        IGRAPH_ADJ_MAX,
+        IGRAPH_ADJ_PLUS,
+        IGRAPH_ADJ_UPPER /* similar to DIRECTED when unweighted, similar to MAX when weighted */
+    };
+    const char *names[] = { "DIRECTED", "MAX", "PLUS", "UPPER" };
+
+    igraph_matrix_init(&mat, 0, 0);
+
+    igraph_erdos_renyi_game_gnm(&g, vcount, meandeg * vcount / 2, IGRAPH_DIRECTED, IGRAPH_LOOPS_SW | IGRAPH_MULTI_SW,
+                                false);
+    igraph_get_adjacency(&g, &mat, IGRAPH_GET_ADJACENCY_BOTH, NULL, IGRAPH_LOOPS_ONCE);
+
+    igraph_vector_init(&weights, igraph_ecount(&g));
+
+    igraph_destroy(&g);
+
+    for (size_t i=0; i < sizeof(types) / sizeof(types[0]); i++) {
+        snprintf(msg, sizeof(msg) / sizeof(msg[0]),
+                 "%2d vcount=%" IGRAPH_PRId ", meandeg=%3" IGRAPH_PRId ", %8s, unweighted, %" IGRAPH_PRId "x",
+                 (int) i+1, vcount, meandeg, names[i], rep);
+
+        BENCH(msg, REPEAT(adjacency(&mat, types[i], IGRAPH_LOOPS_ONCE), rep));
+
+        snprintf(msg, sizeof(msg) / sizeof(msg[0]),
+                 "%2d vcount=%" IGRAPH_PRId ", meandeg=%3" IGRAPH_PRId ", %8s,   weighted, %" IGRAPH_PRId "x",
+                 (int) i+1, vcount, meandeg, names[i], rep);
+
+        BENCH(msg, REPEAT(weighted_adjacency(&mat, types[i], &weights, IGRAPH_LOOPS_ONCE), rep));
+    }
+    printf("\n");
+
+    igraph_vector_destroy(&weights);
+    igraph_matrix_destroy(&mat);
+}
+
+int main(void) {
+
+    igraph_rng_seed(igraph_rng_default(), 137);
+    BENCH_INIT();
+
+    run_bench(100, 5, 10000);
+    run_bench(100, 50, 10000);
+    run_bench(1000, 5, 100);
+    run_bench(1000, 50, 100);
+    run_bench(1000, 500, 100);
+    run_bench(10000, 5, 1);
+    run_bench(10000, 50, 1);
+    run_bench(10000, 500, 1);
+
+    return 0;
+}