File:Amoeba2.svg

Summary

Description
English: The amoeba of
Date
Source Own work based on: Amoeba2.png:  by Oleg Alexandrov
Author
Original:
 
Vector:
Category:Vectorizations
SVG development
InfoField
 The source code of this SVG is invalid due to 2 errors.
Category:Invalid SVG created with Text Editor:Trigonometry
 This trigonometry was created with a text editor.
 This trigonometry is a retouched picture, which means that it has been digitally altered from its original version. Modifications: Vectorization. The original can be viewed here: Amoeba2.png: . Modifications made by Zerodamage.

Category:SVG retouched pictures from raster#Amoeba2.svg

Licensing

Zerodamage, the copyright holder of this work, hereby publishes it under the following license:
w:en:Creative Commons
attribution
This file is licensed under the Creative Commons Attribution 3.0 Unported license.
Attribution:
Zerodamage
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
Category:CC-BY-3.0#Amoeba2.svgCategory:Self-published work

C++ code

#include <iostream>
#include <fstream>
#include <cmath>
#include <complex>
using namespace std;

double small = 1e-14;
double mylog (double);
int main(){

  double A=-5, B=5;
  int N=1000;

  double h= (B-A)/(N-1);
  double theta0 = 2*M_PI/(N-1.0);

  ofstream mfile ("data.txt");

  for (int i=0 ; i < N ; i++){
    double r = exp(A+i*h);

    for (int j=0 ; j < N ; j++){
      double theta = j*theta0;

      complex<double> z2 = polar(r, theta);
      complex<double> root = sqrt(25.0*z2*z2-12.0*(z2*z2*z2+1.0));
      complex<double> z11 = (-5.0*z2+root)/6.0;
      complex<double> z12 = (-5.0*z2-root)/6.0;

      double a1 = mylog(abs(z11));
      double a2 = mylog(abs(z12));
      double b  = mylog(abs(z2));

      mfile << a1  << ' ' << b << endl;
      mfile << a2  << ' ' << b << endl;
    }
  }
  mfile.close();

  return 0;
}
double mylog (double x){

  if (x< 0){
    cerr << "Error in log, negative x!" << endl;
    exit(0);
  }

  if (x < small){
    return log (small);
  }

  return log (x);

}

Matlab code which reads the data output by the C++ code and graphs it

A=load('data.txt');

plot(A(:, 1), A(:, 2), '.');
axis equal; axis off;

axis([-4 6 -5 5])
saveas(gcf, 'amoeba2.eps', 'psc2');

Original upload log

This image is a derivative work of the following images:

Uploaded with derivativeFX Category:Uploaded with derivativeFX

Category:Amoeba (mathematics) Category:Images with C++ source code Category:Images with Matlab source code
Category:Amoeba (mathematics) Category:CC-BY-3.0 Category:Images with C++ source code Category:Images with Matlab source code Category:Invalid SVG created with Text Editor:Trigonometry Category:Pages with syntax highlighting errors Category:SVG retouched pictures from raster Category:Self-published work Category:Uploaded with derivativeFX Category:Vectorizations