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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:24:48 +0000 |
commit | cca66b9ec4e494c1d919bff0f71a820d8afab1fa (patch) | |
tree | 146f39ded1c938019e1ed42d30923c2ac9e86789 /src/3rdparty/adaptagrams/libcola/tests/scale_free.cpp | |
parent | Initial commit. (diff) | |
download | inkscape-upstream.tar.xz inkscape-upstream.zip |
Adding upstream version 1.2.2.upstream/1.2.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/3rdparty/adaptagrams/libcola/tests/scale_free.cpp')
-rw-r--r-- | src/3rdparty/adaptagrams/libcola/tests/scale_free.cpp | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/src/3rdparty/adaptagrams/libcola/tests/scale_free.cpp b/src/3rdparty/adaptagrams/libcola/tests/scale_free.cpp new file mode 100644 index 0000000..d9c2934 --- /dev/null +++ b/src/3rdparty/adaptagrams/libcola/tests/scale_free.cpp @@ -0,0 +1,135 @@ +/* + * vim: ts=4 sw=4 et tw=0 wm=0 + * + * libcola - A library providing force-directed network layout using the + * stress-majorization method subject to separation constraints. + * + * Copyright (C) 2006-2008 Monash University + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library in the file LICENSE; if not, + * write to the Free Software Foundation, Inc., 59 Temple Place, + * Suite 330, Boston, MA 02111-1307 USA + * +*/ + +// generates a random graph with a power-law distribution of node degrees +// the algorithm is pretty much the Barabasi-Albert model but with an extra step +// so that I can guarantee the number of nodes in the graph. +// We begin with an initial chain of m nodes. +// Then, we add new nodes, connecting them to existing nodes v with probability +// degree(v)/(sum all degrees) +// We perform an extra step, looking for disconnected nodes, connecting them +// to other nodes again with probability dependent on degree +#include<iostream> +#include<vector> +#include <cmath> +#include <time.h> +#include <valarray> + +#include "graphlayouttest.h" + +void scale_free(const unsigned n = 50) { + const unsigned m = 3; // begin with a chain of m nodes + const double g=0.08; // edge density, every time we add a node we add 1+g*rand(0-1) edges + // connecting them to existing nodes with probability based on degree + unsigned d[n]; + double defaultEdgeLength=100; + vector<Edge> es; + CompoundConstraints cx,cy; + for(unsigned i=0;i<n;i++) { + d[i]=0; + } + unsigned sumdegree=0; + for(unsigned i=1;i<m;i++) { + es.push_back(make_pair(i-1,i)); + d[i]++;d[i-1]++; + sumdegree+=2; + } + srand(3); + for(unsigned i=2;i<n;i++) { + for(unsigned j=0;j<i;j++) { + double p=(double)d[j]/(double)sumdegree; + double r=(double)rand()/(double)RAND_MAX; + if(r*p>g) { + es.push_back(make_pair(j,i)); + d[j]++;d[i]++; + sumdegree+=2; + } + } + } + for(unsigned i=0;i<n;i++) { + if(d[i]==0) { + double maxP=0; + unsigned end=0; + for(unsigned j=0;j<n;j++) { + if(j==i) continue; + double p=(double)d[j]/(double)sumdegree; + double r=(double)rand()/(double)RAND_MAX; + if(r*p>maxP) { + maxP=r*p; + end=j; + } + } + if(end>i) { + es.push_back(make_pair(i,end)); + } else { + es.push_back(make_pair(end,i)); + } + d[end]++;d[i]++; + sumdegree+=2; + } + } + valarray<double> eweights(es.size()); + sort(d,d+n); + unsigned degree=0,ctr=0; + printf("degree distribution:\n"); + for(unsigned i=0;i<n;i++) { + if(degree!=d[i]) { + if(degree!=0) printf("%d,%d\n",degree,ctr); + degree=d[i]; + ctr=0; + } + ctr++; + } + printf("%d,%d\n",degree,ctr); + for(unsigned i=0;i<es.size();i++) { + unsigned a=es[i].first, b=es[i].second; + eweights[i]=1; + cy.push_back(new SeparationConstraint(a,b,defaultEdgeLength/3)); + } + + cout << "|V|="<<n<<endl; + double width=1000; + double height=1000; + vector<pair<double,double> > startpos(n); + for(unsigned i=0;i<n;i++) { + double x=getRand(width), y=getRand(height); + startpos[i]=make_pair(x,y); + } + const char *f="scalefree"; + //run_test(startpos,es,defaultEdgeLength,cx,cy,CG,false,f,"cg"); + //run_test(startpos,es,defaultEdgeLength,cx,cy,IP,false,f,"ip"); + //run_test(startpos,es,defaultEdgeLength,cx,cy,UGP,false,f,"ugp"); + //run_test(startpos,es,defaultEdgeLength,cx,cy,SGP,false,f,"sgp"); + //run_test(startpos,es,defaultEdgeLength,cx,cy,IP,true,f,"cip"); + //run_test(startpos,es,defaultEdgeLength,cx,cy,UGP,true,f,"cugp"); + run_test(startpos,es,defaultEdgeLength,cx,cy,SGP,true,f,"csgp"); +} +int main() { + for(unsigned i=1;i<2;i++) { + scale_free(i*50); + } + return 0; +} +// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=4:softtabstop=4:textwidth=99 : |