00001
00002 #include "stdinc.h"
00003
00004 main(int argc, char** argv)
00005 {
00006 if (argc < 3) {
00007 cerr << "usage: perturb ecc\n";
00008 exit(1);
00009 }
00010
00011 real a = 1;
00012 real m = 1;
00013 real e = atof(argv[1]);
00014 real th = atof(argv[2]);
00015
00016 cerr << "e = " << e << " th = " << th << endl;
00017
00018 real E = -0.5*m/a;
00019 real r = a*(1-e*e)/(1+e*cos(th));
00020 real rp = a*(1-e);
00021 real ra = a*(1+e);
00022
00023 cerr << "E = " << E << " r = " << r << endl;
00024 cerr << "rp = " << rp << " ra = " << ra << endl;
00025
00026 real j0 = M_PI/2 + asin((r/a-1)/e);
00027 real y = r - rp;
00028
00029 cerr << "j0 = " << j0 << " y = " << y << endl;
00030
00031 real coeff = -1.5*a*a/(e*sqrt(2*abs(E)));
00032 real term1 = e*e*j0;
00033 real term2 = sqrt((ra-r)*(r-rp))*(2-e*e+y/(3*a));
00034
00035 cerr << "coeff = " << coeff << " term1 = " << term1
00036 << " term2 = " << term2 << endl;
00037
00038 cerr << "result = " << coeff * (term1 - term2) << endl;
00039 }
