File:TaniaTaylor0T.png

Complex map of the polynomial of 7th power
 * $ f=1 $ $

+\frac{z}{2}$ $ +\frac{z^2}{16}$ $ -\frac{z^3}{192}$ $ -\frac{z^4}{3072}$ $ +\frac{13 z^5}{61440}$ $ -\frac{47 z^6}{1474560}$ $ +\frac{73 z^7}{41287680}$ representing the truncated Taylor expansion of the Tania function at $z\!=\!0~$.

The function is shown in the coordinates $x\!=\!\Re(z)$, $y\!=\!\Im(z)$ for $|z|\!<\!7$ with lines $u\!=\Re(f)\!=\!\mathrm{const}~$ and lines $v\!=\Im(f)\!=\!\mathrm{const}~$.

The range where the Taylor approximation returns less than 3 signifivant figures is shaded.

Generators
The files ado.cin and conto.cin should be in the working directory.

Common headers
using namespace std; typedef complex z_type;
 * 1) include 
 * 2) include 
 * 3) include 
 * 4) define DB double
 * 5) define DO(x,y) for(x=0;x<y;x++)
 * 1) include
 * 1) define Re(x) x.real
 * 2) define Im(x) x.imag
 * 3) define I z_type(0.,1.)
 * 4) include "conto.cin"

z_type ArcTania(z_type z) {return z + log(z) - 1. ;} z_type ArcTaniap(z_type z) {return 1. + 1./z ;}

z_type TaniaTay(z_type z) { int n; z_type s; s=1.+z*(.5+z*(1./16.+z*(-1./192.+z*(-1./3072.+z*(1.3/6144.+z*(-4.7/147456. //+z*(7.3/4128768.) //some reserve term )))))); DO(n,3) s+=(z-ArcTania(s))/ArcTaniap(s); return s ; }

z_type TaniaTaylor(z_type z) { int n; z_type s; s=1.+z*(.5+z*(1./16.+z*(-1./192.+z*(-1./3072.+z*(1.3/6144.+z*(-4.7/147456. +z*(7.3/4128768.) //some reserve term )))))); // DO(n,3) s+=(z-ArcTania(s))/ArcTaniap(s); return s ; }

z_type TaniaNega(z_type z){int n;z_type s=exp(z-exp(z)+1.); DO(n,4) s+=(z-ArcTania(s))/ArcTaniap(s); return s ; }

z_type TaniaNeg(z_type z){int n; z_type e=exp(1.+z); return e*(1.+e*(-1.+e*(1.5+e*(-3.5 )))); } // return e*(1.+e*(-1.+e*(1.5))); } // return e*(1.+e*(-1.)); } // return e; }

z_type TaniaBigI(z_type z){ int n; z_type t=1.+z; z_type L=log(t); z_type x=L/t; z_type m=1./L; z_type s = t-L + x*(1. + x*( .5-m + x*( 1./3. + m*(-1.5+m) +x*( .25 +m*(-11./6.+m*(3.-m)) )))); DO(n,4) s+=(z-ArcTania(s))/ArcTaniap(s); return s ; }

z_type TaniaBig1(z_type z){ z_type t=1.+z; z_type L=log(t); z_type x=L/t; z_type m=1./L; z_type s = t-L + x*(1. + x*( .5-m + x*( 1./3. + m*(-1.5+m) +x*( .25 +m*(-11./6.+m*(3.-m)) )))); return s ; }

z_type TaniaBig0(z_type z){int n;z_type L=log(z), s=z-L+1.; s-=(1.-L)/z; return s ; }

z_type TaniaS(z_type z){int n; z_type s,t=z+z_type(2.,-M_PI);t*=2./9.; t=I*sqrt(t); s=-1.+t*(3.+t*(-3.+t*(.75+t*(.3+t*(.9/16.+t*(-.3/7.+t*(-12.51/224. //+t*(-.9/28.) ))))))); DO(n,3) s+=(z-ArcTania(s))/ArcTaniap(s); return s ; }

z_type TaniaSingu(z_type z){int n; z_type s,t=z+z_type(2.,-M_PI);t*=2./9.; t=I*sqrt(t); s=-1.+t*(3.+t*(-3.+t*(.75+t*(.3+t*(.9/16.+t*(-.3/7.+t*(-12.51/224. +t*(-.9/28.) ))))))); }

z_type Tania(z_type z){ z_type t; if( fabs(Im(z))< M_PI && Re(z)<-2.51) return TaniaNega(z); if( abs(z)>7. || Re(z)>3.8 ) return TaniaBigI(z); if( Im(z) > .7 ) return TaniaS(z); if( Im(z) < -.7) return conj(TaniaS(conj(z))); return TaniaTay(z); }

Generator of shading
main{ int j,k,m,n; DB x,y, p,q, t; z_type z,c,d; int M=160,M1=M+1; int N=161,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("taniataylor0d2.eps","w");ado(o,162,162); fprintf(o,"81 81 translate\n 10 10 scale\n"); DO(m,M1)X[m]=-8.+.1*(m); DO(n,N1)Y[n]=-8.+.1*(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=TaniaTaylor(z); d=Tania(z); // c=ArcTania(c); p=-log( abs(c-d) / (abs(c)+abs(d)) )/log(10.) ; //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;} }} M(-8.1,-8.1)L(-8.1,8.1)L(8.1,8.1)L(8.1,-8.1) fprintf(o,"C 1 .9 .9 RGB F\n"); fprintf(o,"1 setlinejoin 2 setlinecap\n"); p=6;q=.5; /* conto(o,g,w,v,X,Y,M,N, (1),-p,p); fprintf(o,".1 W .6 .5 0 RGB S\n"); conto(o,g,w,v,X,Y,M,N, (2),-p,p); fprintf(o,".01 W 0 0 0 RGB S\n"); */ conto(o,g,w,v,X,Y,M,N, (3),-p,p); fprintf(o,"C 1 1 1 RGB F\n"); for(m=-8;m<9;m++){if(m==0){M(m,-8.5)L(m,8.5)} else{M(m,-8)L(m,8)}} for(n=-8;n<9;n++){    M(  -8,n)L(8,n)} fprintf(o,".008 W 0 0 0 RGB S\n"); y= M_PI; for(m=0;m<60;m+=4) {x=-7.95+.1*m; M(x,y) L(x+.05,y)} y=-M_PI; for(m=0;m<60;m+=4) {x=-7.95+.1*m; M(x,y) L(x+.05,y)} fprintf(o,".07 W 1 .5 0 RGB S\n"); y= M_PI; for(m=2;m<60;m+=4) {x=-7.95+.1*m; M(x,y) L(x+.05,y)} y=-M_PI; for(m=2;m<60;m+=4) {x=-7.95+.1*m; M(x,y) L(x+.05,y)} fprintf(o,".07 W 0 .5 1 RGB S\n"); fprintf(o,"showpage\n%c%cTrailer",'%','%'); fclose(o); system("epstopdf taniataylor0D2.eps"); system(   "open taniataylor0D2.pdf"); getchar; system("killall Preview"); }

Generator of curves
int M=160,M1=M+1; int N=161,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("taniataylor0map.eps","w");ado(o,162,162); fprintf(o,"81 81 translate\n 10 10 scale\n"); DO(m,M1) X[m]=-8.+.1*(m); DO(n,80)Y[n]=-8.+.1*n; Y[80]=-.03; Y[81]= .03; for(n=82;n-99. && p<99. && q>-99. && q<99. ){ g[m*N1+n]=p;f[m*N1+n]=q;} }        }} fprintf(o,"1 setlinejoin 2 setlinecap\n");  p=.6;q=.5; for(m=-10;m<10;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<10;m++) conto(o,f,w,v,X,Y,M,N, (0.-m),-p,p); fprintf(o,".05 W .9 0 0 RGB S\n"); for(m=1;m<10;m++) conto(o,f,w,v,X,Y,M,N, (0.+m),-p,p); fprintf(o,".05 W 0 0 .9 RGB S\n"); conto(o,f,w,v,X,Y,M,N, (0. ),-p,p); fprintf(o,".05 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,".05 W 0 0 0 RGB S\n"); y= M_PI; for(m=0;m<60;m+=4) {x=-7.95+.1*m; M(x,y) L(x+.05,y)} y=-M_PI; for(m=0;m<60;m+=4) {x=-7.95+.1*m; M(x,y) L(x+.05,y)} fprintf(o,".07 W 1 .5 0 RGB S\n"); y= M_PI; for(m=2;m<60;m+=4) {x=-7.95+.1*m; M(x,y) L(x+.05,y)} y=-M_PI; for(m=2;m<60;m+=4) {x=-7.95+.1*m; M(x,y) L(x+.05,y)} fprintf(o,".07 W 0 .5 1 RGB S\n"); fprintf(o,"showpage\n%c%cTrailer",'%','%'); fclose(o); system("epstopdf taniataylor0map.eps"); system(   "open taniataylor0map.pdf"); getchar; system("killall Preview"); }

Latex generator of labels
% Copyleft 2011 by Dmitrii Kouznetsov \documentclass[12pt]{article} % \usepackage{geometry} % \usepackage{graphicx} % \usepackage{rotating} % \paperwidth 854pt % \paperheight 844pt % \topmargin -96pt % \oddsidemargin -98pt % \textwidth 1100pt % \textheight 1100pt % \pagestyle {empty} % \newcommand \sx {\scalebox} % \newcommand \rot {\begin{rotate}} % \newcommand \ero {\end{rotate}} % \newcommand \ing {\includegraphics} % \begin{document} % \sx{5}{ \begin{picture}(164,165) % \put(6,5){\ing{taniataylor0d2}} % \put(6,5){\ing{taniataylor0map}} % \put(2,162){\sx{.7}{$y$}} % \put(2,144){\sx{.6}{$6$}} % \put(2,124){\sx{.6}{$4$}} % \put(2,104){\sx{.6}{$2$}} % %\put(3,116){\sx{.6}{$\pi$ ~ \bf cut}} % %\put(23,100){\sx{.8}{$u\!=\!0$}} % \put(2, 84){\sx{.6}{$0$}} % \put(20, 84){\sx{.8}{$v\!=\!0$}} % %\put(23,68){\sx{.8}{$u\!=\!0$}} % \put(-3,64){\sx{.6}{$-2$}} % %\put(-3,53){\sx{.6}{$-\pi$ ~ \bf cut}} % \put(-3,44){\sx{.6}{$-4$}} % \put(-3,24){\sx{.6}{$-6$}} % \put( 22,0){\sx{.6}{$-6$}} % \put( 42,0){\sx{.6}{$-4$}} % \put( 62,0){\sx{.6}{$-2$}} % \put( 86,0){\sx{.6}{$0$}} % \put(106,0){\sx{.6}{$2$}} % \put(126,0){\sx{.6}{$4$}} % \put(146,0){\sx{.6}{$6$}} % \put(164,0){\sx{.7}{$x$}} % %\put(139,154){\rot{-6}\sx{.8}{$v\!=\!6$}\ero}% %\put(138,143){\rot{-6}\sx{.8}{$v\!=\!5$}\ero}% %\put(137,132){\rot{-6}\sx{.8}{$v\!=\!4$}\ero}% \put(136,121){\rot{-6}\sx{.8}{$v\!=\!3$}\ero}% \put(135,109){\rot{-5}\sx{.8}{$v\!=\!2$}\ero}% \put( 89, 80){\rot{85}\sx{.8}{$u\!=\!1$}\ero}% \put(106, 78){\rot{87}\sx{.8}{$u\!=\!2$}\ero}% \put(121, 78){\rot{89}\sx{.8}{$u\!=\!3$}\ero}% \put(134, 97){\rot{-4}\sx{.8}{$v\!=\!1$}\ero}% \put(134, 84){\rot{0}\sx{.8}{$v\!=\!0$}\ero}% \put(134, 72){\rot{3}\sx{.72}{$v\!=\!-\!1$}\ero}% \put(133, 60){\rot{3}\sx{.72}{$v\!=\!-\!2$}\ero}% \put(134, 48){\rot{3}\sx{.72}{$v\!=\!-\!3$}\ero}% %\put(135, 36){\rot{3}\sx{.72}{$v\!=\!-\!4$}\ero}% %\put(136, 25){\rot{3}\sx{.72}{$v\!=\!-\!5$}\ero}% %\put(137, 14){\rot{3}\sx{.72}{$v\!=\!-\!6$}\ero}% \end{picture} % } % \end{document}

Generation of PNG
The pdf file created a the compilation of the latex source was converted to PNG with default resolution.