/**
* 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
* .
*
* (c) Vincenzo Nicosia 2009-2017 --
*
* 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
*
***********************************************************************
*
* This program implements the Dorogovtsev-Samukhin-Mendes preferential
* attachment, where the attachment probability is:
*
* \Pi_{i->j} \propto k_j + a
*
* Here a > -m is a tunable parameter. The resulting network has a
* powerlaw degree distribution with exponent:
*
* \gamma = 3 + a/m
*
* References:
*
* [1] S. N. Dorogovtsev, J. F. F. Mendes, A. N. Samukhin. "Structure
* of Growing Networks with Preferential Linking".
* Phys. Rev. Lett. 85 (2000), 4633-4636.
*
*/
#include
#include
#include
#include "cum_distr.h"
void usage(char *argv[]){
printf("********************************************************************\n"
"** **\n"
"** -*- dms -*- **\n"
"** **\n"
"** Grow a scale-free network of 'N' nodes using the modified **\n"
"** linear preferential attachment model proposed by **\n"
"** Dorogovtsev-Mendes-Samukhin. **\n"
"** **\n"
"** The initial network is a clique of 'n0' nodes, and each new **\n"
"** node creates 'm' edges. The attachment probability is of **\n"
"** the form: **\n"
"** **\n"
"** P(i->j) ~ k_j + a **\n"
"** **\n"
"** where a > -m is the fourth parameter. The resulting **\n"
"** network will have a power-law degree distribution with **\n"
"** exponent **\n"
"** **\n"
"** gamma = 3 + a/m **\n"
"** **\n"
"** The program prints on STDOUT the edge-list of the final **\n"
"** graph. **\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"
" (c) Vincenzo Nicosia 2009-2017 (v.nicosia@qmul.ac.uk)\n\n"
"********************************************************************\n\n"
);
printf("Usage: %s \n", argv[0]);
}
int init_network(unsigned int *I, unsigned int *J, int n0,
double a, cum_distr_t *d){
unsigned int n, i, S_num;
S_num = 0;
for(n=0; n n0){
fprintf(stderr, "n0 cannot be smaller than m\n");
exit(1);
}
if (n0<1){
fprintf(stderr, "n0 must be positive\n");
exit(1);
}
if (m < 1){
fprintf(stderr, "m must be positive\n");
exit(1);
}
if (a < -m){
fprintf(stderr, "a must be larger than -m\n");
exit(1);
}
I = malloc(N * m * sizeof(unsigned int));
J = malloc(N * m * sizeof(unsigned int));
K = dms(I, J, N, m, n0, a);
for(i=0; i