File:MoriplotFragment.jpg

#include <stdio.h>
#include <math.h>
#include<stdlib.h>
//#include "scft.cin"
#define DB double
#include "ado.cin"
DB L1= 2.404825557695773;
DB L2= 5.5200781102863115;
DB L3= 8.653727912911013;
DB L4=11.791534439014281;
//DB mory(DB x){ return j0(x)/(1.-(1./(L1*L1))*x*x);} // mory also could be principal, but for graphics mori is better.
DB morin(DB x){ return j0(L1*x)/(1-x*x);} // naive representation fails at x=1.
DB mori0(DB x){ int n,m; DB s, xx=x*x;
DB c[16]={ 1., -0.4457964907366961303, 0.07678538241994023453, -0.0071642885058902232688,
0.00042159522055140947688, -0.000017110542281627483109, 5.0832583976057607495e-7, -1.1537378620148452816e-8,
2.0662789231930073316e-10, -2.9948657413756059965e-12, 3.5852738451127332173e-14,-3.6050239634659700777e-16,
3.0877184831292878827e-18, -2.2798156440952688462e-20, 1.4660907878585489441e-22,-8.2852774398657968065e-25};
// 16th term seems to fail; perhaps, due to the C++ rounding errors.
//with m=15, at |x|<2, the relative error is of order of 10^(-16)
//In this sense, the result is accurate while |x|<2.
m=15; s=c[m]*xx; for(n=m-1;n>0;n--){ s+=c[n]; s*=xx;}
return 1.+s;}
DB mori(DB x){if(fabs(x)<2.) return mori0(x);
                        return morin(x);}

int main(){ int i; //double a[NP+1],b[NP+1]; double d=sqrt(M_PI/NP);
//double x,y,f,g; FILE *o; o=fopen("08.eps","w"); ado(o,620,820);
double x,y,f,g; FILE *o; o=fopen("moriplo.eps","w"); ado(o,620,120);
#define M(x,y) fprintf(o,"%9.4lf %9.4lf M\n",x+0.,y+0.);
#define L(x,y) fprintf(o,"%9.4lf %9.4lf L\n",x+0.,y+0.);
fprintf(o,"10 10 translate 100 100 scale 2 setlinecap 1 setlinejoin\n");
for(i=0;i<12;i++){M(.5*i,0)L(.5*i,1)}
for(i=0;i<3;i++){M(0,.5*i)L(5.5,.5*i)} fprintf(o,".006 W S\n");
M(L2/L1,1)L(L2/L1,-.04)
M(L1,1)L(L1,-.04)
M(L3/L1,1)L(L3/L1,-.04)
M(L4/L1,1)L(L4/L1,-.04)
fprintf(o,".003 W S\n");
for(i=0;i<101;i++){x=.01*L1*i; y=j0(x); if(i==0)M(x,y) else L(x,y); } L(L1,0)L(618,0) fprintf(o,".009 W 1 0 0 RGB S\n");
//for(i=0;i<122;i++){x=.05*(i-.1);y=morin(x); if(i==0)M(x,y) else L(x,y);} fprintf(o,".009 W 0 0 1 RGB S\n");
//for(i=0;i<122;i++){x=.05*(i-.1);y=mori0(x); if(i==0)M(x,y) else L(x,y); if(fabs(y)>1) break;} fprintf(o,".009 W 0 .9 0 RGB S\n");
for(i=0;i<122;i++){x=.05*i;y=mori(x); if(i==0) M(x,y) else L(x,y); if(fabs(y)>1) break;} fprintf(o,".009 W 0 0 1 RGB S\n");
/*
for(i=1;i<640;i++){ x=.01*(i-.5); f=mori0(x); g=morin(x); if(f==g){y=9.;}
        else { y=-log(fabs(f-g)/(fabs(f)+fabs(g))); y/=log(10.); y/=2.;};
if(i==1)M(x,y) else L(x,y); printf("%5.2lf %20.14lf %20.14lf %10.4lf\n",x,f,g,y);}
fprintf(o,".008 W 0 0 0 RGB S\n"); // this is agreement of functions morin and mori0; important at the testing.
*/
fprintf(o,"showpage\n%c%cTrailer\n",'%','%'); fclose(o);
system("epstopdf moriplo.eps");
system( "open moriplo.pdf");
}