diff options
Diffstat (limited to 'src/graph_info/graph_info.c')
| -rw-r--r-- | src/graph_info/graph_info.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/src/graph_info/graph_info.c b/src/graph_info/graph_info.c new file mode 100644 index 0000000..3fc0ec6 --- /dev/null +++ b/src/graph_info/graph_info.c @@ -0,0 +1,130 @@ +/** + * 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 3 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 + * <http://www.gnu.org/licenses/>. + * + * (c) Vincenzo Nicosia 2009-2017 -- <v.nicosia@qmul.ac.uk> + * + * This file is part of NetBunch, a package for complex network + * analysis and modelling. For more information please visit: + * + * http://www.complex-networks.net/ + * + * If you use this software, please add a reference to + * + * V. Latora, V. Nicosia, G. Russo + * "Complex Networks: Principles, Methods and Applications" + * Cambridge University Press (2017) + * ISBN: 9781107103184 + * + *********************************************************************** + * + * Compute and print the basic properties of the undirected graph on + * input, i.e., the number of nodes, the number of edges, and the + * first two uncentered moments of the degree sequence (<k> and + * <k^2>). + * + */ + + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "utils.h" + + +void usage(char *argv[]){ + + printf("********************************************************************\n" + "** **\n" + "** -*- graph_info -*- **\n" + "** **\n" + "** Compute basic information about the 'graph_in', namely the **\n" + "** number of nodes, number of edges, average degree, and the **\n" + "** average squared degree. **\n" + "** **\n" + "** The input file 'graph_in' is an edge-list: **\n" + "** **\n" + "** I_1 J_1 **\n" + "** I_2 J_2 **\n" + "** I_3 J_3 **\n" + "** ... ... **\n" + "** I_K J_K **\n" + "** **\n" + "** If 'graph_in' is equal to '-' (dash), read the file from **\n" + "** the standard input (STDIN). **\n" + "** **\n" + "** The output is a single line containing in the format: **\n" + "** **\n" + "** N K avg_k avg_k2 **\n" + "** **\n" + "** where 'N' is the number of nodes, 'K' is the number of **\n" + "** edges, 'avg_k' is the average degree, and 'avg_k2' is the **\n" + "** average of the squared degree. **\n" + "** **\n" + "********************************************************************\n" + " This is Free Software - You can use and distribute it under \n" + " the terms of the GNU General Public License, version 3 or later\n\n" + " Please visit http://www.complex-networks.net for more information\n\n" + " (c) Vincenzo Nicosia 2009-2017 (v.nicosia@qmul.ac.uk)\n" + "********************************************************************\n\n" + ); + printf("Usage: %s <graph_in>\n", argv[0]); +} + + + +double ksquare_mean(unsigned int N, unsigned int *r_slap){ + + double sum = 0; + unsigned int i; + unsigned int k; + for(i=0; i<N; i++){ + k = r_slap[i+1] - r_slap[i]; + sum += k*k; + } + sum /= N; + return sum; +} + + +int main(int argc, char *argv[]){ + + unsigned int N, K; + unsigned int *J_slap, *r_slap; + FILE *filein; + double k2mean; + + if(argc < 2){ + usage(argv); + exit(1); + } + + if (!strcmp(argv[1], "-")){ + /* take the input from STDIN */ + filein = stdin; + } + else { + filein = openfile_or_exit(argv[1], "r", 2); + } + + read_slap(filein, &K, &N, &J_slap, &r_slap); + + fclose(filein); + + k2mean = ksquare_mean(N, r_slap); + printf("%d %d %2.6f %2.6f\n", N, K/2, 1.0*K / N, k2mean); + free(J_slap); + free(r_slap); + +} |