Hermann Stamm-Wilbrandt Hermann-SW

Hermann-SW / dodecahedron.js

Created September 14, 2024 20:52

JSCAD dodecahedron with exact coordinates from Wikipedia and adjacengy lists

	const jscad = require('@jscad/modeling')
	const { colorize } = jscad.colors
	const { sphere, cylinder } = jscad.primitives
	const { rotate, translate } = jscad.transforms
	const { vec3 } = jscad.maths

	er=0.02

	function vertex(p) { return sphere({ center: p, radius: 3*er}) }

Hermann-SW / Fibonacci_prime_indices.gp

Created August 14, 2024 14:01

Fibonacci number prime indices up to largest known sofar fibonacci prime index 201107

Hermann-SW / challenge_sequential_vertex_coloring.cpp

Last active August 14, 2024 23:02

create planar graph that forces arbitrary k colors being used by Boost "sequential_vertex_coloring()" with default order

	/*
	f=challenge_sequential_vertex_coloring
	g++ -O3 -Wall -Wextra -pedantic $f.cpp -o $f
	cpplint --filter=-legal/copyright,-build/namespaces,-runtime/references $f.cpp
	./$f 6 planar? writeLeda 2>C6.u
	GraphvizFiddle.py firefox <(straight_line_graphviz C6.u)
	*/
	#include <boost/graph/sequential_vertex_coloring.hpp>
	#include <boost/graph/adjacency_list.hpp>
	#include <boost/graph/graph_utility.hpp>

Hermann-SW / seqcol.cpp

Created July 30, 2024 10:50

Boost sequential_vertex_coloring() for evaluation on (planar) graphs

	#include <fstream>
	#include <boost/graph/sequential_vertex_coloring.hpp>
	#include <boost/graph/adjacency_list.hpp>
	#include <boost/graph/graph_utility.hpp>

	using namespace boost;

	template <class graphType>
	void
	read_leda_graph(graphType& g, char* gname) {

Hermann-SW / 8c.u

Created July 30, 2024 10:48

22 vertices, 54 edges planar graph that makes Boost sequential_vertex_coloring() use 8 colors

Hermann-SW / 7c.u

Created July 30, 2024 10:47

14 vertices, 31 edges planar graph that makes Boost sequential_vertex_coloring() use 7 colors

Hermann-SW / miniball_int.cpp

Created July 9, 2024 20:04

Determination of convex set diameter with Miniball.hpp

	#include <cstdlib>
	#include <iostream>
	#include <math.h>
	#include "Miniball.hpp"
	// from https://people.inf.ethz.ch/gaertner/subdir/software/miniball.html
	/*
	$ g++ miniball_int.cpp -O3 -o miniball_int
	$
	*/
	int main (int argc, char* argv[])

Hermann-SW / SquaresRepresentations.gp

Last active July 8, 2024 07:00

Representatins of n as sum of k squares (non-negative monotonic increasing, all, count)

	assert(b)=if(!(b),error());

	SquaresRepresentations(n,k,a=0)={
	my(R=List(),m=sqrtint(n\k));
	if(k==1,return(if(m>=a&&n==m^2,[m],[])));
	for(b=a,m,foreach(SquaresRepresentations(n-b^2,k-1,b),s,listput(R,concat([b],s))));
	Vec(R);
	}

	signs(a)={

Hermann-SW / 131072.gp

Last active June 4, 2024 18:12

1108 Generalized Fermat prime bases with exponent 131072 from t5k.org

Hermann-SW / Fermat.gp

Last active June 29, 2024 19:50

Prime factors of Fermat numbers F0..F30

	F__={[\\ needs parisizemax >= 600M; from http://www.prothsearch.com/fermat.html
	[3], \\ F0
	[5],
	[17],
	[257],
	[65537],
	[641, 6700417],
	[274177, 67280421310721],
	[59649589127497217, 5704689200685129054721],
	[1238926361552897, "P62"],