File:CoshcmapT120.png

Complex map of function Coshc

$f=\mathrm{coshc}(x+\mathrm i y)$;

is shown with levels $u=\Re(f)=\mathrm{const}$ and levels $u=\Re(f)=\mathrm{const}$ are drqwn in the $x$, $y$ plane.

C++ generator of curves

Files ado.cin and conto.cin should be loaded in the working directory for the compilation of the C++ code below.

#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#define DB double
#define DO(x,y) for(x=0;x<y;x++)
using namespace std;
#include <complex>
typedef complex<double> z_type;
#define Re(x) x.real()
#define Im(x) x.imag()
#define I z_type(0.,1.)
#include "conto.cin"

/*

z_type acos(z_type z){
if(Im(z)<0){if(Re(z)>=0){return I*log( z + sqrt(z*z-1.) );} 
                   else{return I*log( z - sqrt(z*z-1.) );}}
           if(Re(z)>=0){return -I*log( z + sqrt(z*z-1.) );} 
                  else {return -I*log( z - sqrt(z*z-1.) );} }

z_type asin(z_type z){
if(Im(z)<0){if(Re(z)>=0){return M_PI/2.-I*log( z + sqrt(z*z-1.) );} 
                   else {return M_PI/2.-I*log( z - sqrt(z*z-1.) );}}
           if(Re(z)>=0){return M_PI/2.+I*log( z + sqrt(z*z-1.) );} 
                  else {return M_PI/2.+I*log( z - sqrt(z*z-1.) );} }

• /

main(){ int j,k,m,n; DB x,y, p,q, t; z_type z,c,d;
int M=401,M1=M+1;
int N=401,N1=N+1;
DB X[M1],Y[N1], g[M1*N1],f[M1*N1], w[M1*N1]; // w is working array.
char v[M1*N1]; // v is working array
FILE *o;o=fopen("coshcmap.eps","w");ado(o,82,82);
fprintf(o,"41 41 translate\n 10 10 scale\n");
//DO(m,M1) X[m]=-4.+.02*(m-.5);
DO(n,200)Y[n]=-4.+.02*n;
     Y[200]=-.002;
     Y[201]= .002;
for(n=202;n<N1;n++) Y[n]=-4.+.02*(n-1.);
DO(m,M1)X[m]=Y[m];
for(m=-4;m<5;m++){if(m==0){M(m,-4.1)L(m,4.1)} else{M(m,-4)L(m,4)}}
for(n=-4;n<5;n++){     M(  -4,n)L(4,n)}
fprintf(o,"2 setlinecap .008 W 0 0 0 RGB S\n");
DO(m,M1)DO(n,N1){g[m*N1+n]=9999; f[m*N1+n]=9999;}
DO(m,M1){x=X[m]; //printf("%5.2f\n",x);
DO(n,N1){y=Y[n]; z=z_type(x,y);
//     c=asin(z);
     c=cosh(z)/z;
     p=Re(c);
     q=Im(c);        
     if(p>-99. && p<99.  &&  q>-99. && q<99 )
{ g[m*N1+n]=p; 
  f[m*N1+n]=q;
 }
                     }}
// #include "plofu.cin"
fprintf(o,"1 setlinejoin 1 setlinecap\n"); p=1.8;q=.7;
for(m=-11;m<11;m++)for(n=2;n<10;n+=2)conto(o,f,w,v,X,Y,M,N,(m+.1*n),-q, q); fprintf(o,".01 W 0 .6 0 RGB S\n");
for(m=0;m<10;m++) for(n=2;n<10;n+=2)conto(o,g,w,v,X,Y,M,N,-(m+.1*n),-q, q); fprintf(o,".01 W .9 0 0 RGB S\n");
for(m=0;m<10;m++) for(n=2;n<10;n+=2)conto(o,g,w,v,X,Y,M,N, (m+.1*n),-q, q); fprintf(o,".01 W 0 0 .9 RGB S\n");
for(m=1;m<11;m++)  conto(o,f,w,v,X,Y,M,N, (0.-m),-p,p); fprintf(o,".03 W .9 0 0 RGB S\n");
for(m=1;m<11;m++)  conto(o,f,w,v,X,Y,M,N, (0.+m),-p,p); fprintf(o,".03 W 0 0 .9 RGB S\n");
               conto(o,f,w,v,X,Y,M,N, (0.  ),-p,p); fprintf(o,".03 W .6 0 .6 RGB S\n");
for(m=-9;m<10;m++) conto(o,g,w,v,X,Y,M,N, (0.+m),-p,p); fprintf(o,".03 W 0 0 0 RGB S\n");
//
/*
M(-4.02,0)L(-1,0)
M(1,0)L(4.02,0)
fprintf(o,"0 setlinecap .028 W .9 1 .9 RGB S\n");
DO(m,31){x=-1.-.1*m; M(x,0) L(x-.05,0)}
DO(n,31){x= 1.+.1*n; M(x,0) L(x+.05,0)}
fprintf(o,".032 W 0 0 0 RGB S\n");
*/
fprintf(o,"showpage\n%c%cTrailer",'%','%'); fclose(o);
     system("epstopdf coshcmap.eps");
     system(    "open coshcmap.pdf");            
     getchar(); system("killall Preview");//for mac
}

Latex generator of labels

File coshcmap.pdf should be generated with the code above in order to compile the Latex document below. \documentclass[12pt]{article} % <br> \paperheight 838px % <br> \paperwidth 844px % <br> \textwidth 1294px % <br> \textheight 1200px % <br> \topmargin -80px % <br> \oddsidemargin -80px % <br> \usepackage{graphics} % <br> \usepackage{rotating} % <br> \newcommand \sx {\scalebox} % <br> \newcommand \rot {\begin{rotate}} % <br> \newcommand \ero {\end{rotate}} % <br> \newcommand \ing {\includegraphics} % <br> \newcommand \rmi {\mathrm{i}} % <br> \begin{document} % <br> \newcommand \zoomax { % <br> \put(16,820){\sx{4.4}{$y$}} % <br> \put(16,630){\sx{4}{$2$}} % <br> \put(16,430){\sx{4}{$0$}} % <br> \put(-4, 230){\sx{4}{$-\!2$}} % <br> \put(220, 5){\sx{4}{$-\!2$}} % <br> \put(443, 5){\sx{4}{$0$}} % <br> \put(643, 5){\sx{4}{$2$}} % <br> \put(831,6){\sx{4}{$x$}} % <br> } % <br> \parindent 0pt % <br> \begin{picture}(816,816) % <br> \put(40,30){\sx{10}{\ing{coshcmap}}} % <br> \zoomax % <br> \put(415,724){\sx{3}{$u\!=\!0$}} % <br> \put(415,164){\sx{3}{$u\!=\!0$}} % <br> \put(450,620){\sx{3}{\rot{90}$u\!=\!0$\ero}} % <br> % <br> \put(274,594){\sx{3}{\rot{80}$v\!=\!1$\ero}} % <br> \put(256,394){\sx{3}{\rot{90}$u\!=\!-2$\ero}} % <br> \put(298,432){\sx{3}{\rot{-.1}$v\!=\!0$\ero}} % <br> % <br> \put(580,406){\sx{3}{\rot{90}$v\!=\!0$\ero}} % <br> \put(666,406){\sx{3}{\rot{90}$u\!=\!2$\ero}} % <br> \end{picture} % <br> \end{document} % <br>