[Tex/LaTex] Tangent plot on tikz

tikz-pgf

\documentclass[12pt,a4paper]{article}
\usepackage{graphicx}
\usepackage{amsmath,amssymb}
\usepackage{tikz}



\begin{figure}[H]
\begin{center}
\begin{tikzpicture}[scale=1.2,smooth,domain=-2*pi:2*pi];
% First line looks reasonable
\draw[blue = solid,  thick ] plot   [domain=0:5*pi/12](\x,{tan(\x r)});
% second line is not goo
\draw[blue = solid,  thick ] plot    [domain=27*pi/45:17*pi/12](\x,{tan(\x r)});

\draw[blue = solid,  thick ] plot   [domain=1.6*pi:29*pi/12](\x,{tan(\x r)});

\end{tikzpicture}
\caption{Graph of $y = \tan\theta$}
\label{fig:graphtan}
\end{center}
\end{figure}

Best Answer

The following is PSTricks' solution. Just for fun!

Features

The feature I propose here is that you can determine the dimension of diagram in advance. For example, the total width must be 10 cm and its height must be 4 cm. You can also specify offsets to make the border, labels, and arrows have enough spaces and balanced.

Output

enter image description here

User Interface

\def\f(#1){tan(#1)}% function to plot
\def\g[#1]{cos(#1)}% function to plot
\def\h#1{sin(#1)}% function to plot

\const{Width}{10}% total width in cm
\const{Height}{4}% total height in cm 

\const{POL}{-0.20}% pspicture left offset in cm
\const{POR}{ 0.50}% pspicture right offset in cm
\const{POB}{-0.20}% pspicture bottom offset in cm
\const{POT}{ 0.50}% pspicture top offset in cm

\const{AOL}{-0.20}% axis left offset in cm
\const{AOR}{ 0.30}% axis right offset in cm
\const{AOB}{-0.20}% axis bottom offset in cm
\const{AOT}{ 0.30}% axis top offset in cm

\const{DomL}{-2*pi}% domain left  
\const{DomR}{2*pi}% domain right  
\const{DomB}{-2}% domain bottom  
\const{DomT}{ 2}% domain top 

\const[0]{TrigLabelBase}{2}% denominator for a fraction of pi

User Interface Explanation

Note that the following diagram uses different values to provide spaces for annotations. If you are trying to map the values described above to the corresponding annotations below, then you are comparing orange with banana!

enter image description here

Complete Code

\documentclass[border=0pt,pstricks]{standalone}
\usepackage{pst-eucl,pstricks-add}
\usepackage[nomessages]{fp}
\newcommand\const[3][3]{\expandafter\FPeval\csname#2\endcsname{round(#3:#1)}}


% User defined data:
\def\f(#1){tan(#1)}% function to plot
\def\g[#1]{cos(#1)}% function to plot
\def\h#1{sin(#1)}% function to plot

\const{Width}{10}% total width in cm
\const{Height}{4}% total height in cm 

\const{POL}{-0.20}% pspicture left offset in cm
\const{POR}{ 0.50}% pspicture right offset in cm
\const{POB}{-0.20}% pspicture bottom offset in cm
\const{POT}{ 0.50}% pspicture top offset in cm

\const{AOL}{-0.20}% axis left offset in cm
\const{AOR}{ 0.30}% axis right offset in cm
\const{AOB}{-0.20}% axis bottom offset in cm
\const{AOT}{ 0.30}% axis top offset in cm

\const{DomL}{-2*pi}% domain left  
\const{DomR}{2*pi}% domain right  
\const{DomB}{-2}% domain bottom  
\const{DomT}{ 2}% domain top 

\const[0]{TrigLabelBase}{2}% denominator for a fraction of pi

% Internal used constants:
\const{XUnit}{(Width-POR+POL-AOR+AOL)/(DomR-DomL)}
\const{YUnit}{(Height-POT+POB-AOT+AOB)/(DomT-DomB)}

\const{PicL}{(POL+AOL)/XUnit+DomL}
\const{PicR}{(POR+AOR)/XUnit+DomR}
\const{PicB}{(POB+AOB)/YUnit+DomB}
\const{PicT}{(POT+AOT)/YUnit+DomT}

\const{AxiL}{AOL/XUnit+DomL}
\const{AxiR}{AOR/XUnit+DomR}
\const{AxiB}{AOB/YUnit+DomB}
\const{AxiT}{AOT/YUnit+DomT}

\const{DeltaX}{pi/TrigLabelBase}

\psset{xunit=\XUnit,yunit=\YUnit,algebraic,plotpoints=500}

\begin{document}


\begin{pspicture}[showgrid=false](\PicL,\PicB)(\PicR,\PicT)
    \psplot[linecolor=red,yMaxValue=\AxiT,yMinValue=\AxiB]{\DomL}{\DomR}{\f(x)}
%    \psplot[linecolor=green]{\DomL}{\DomR}{\g[x]}
%    \psplot[linecolor=blue]{\DomL}{\DomR}{\h{x}}
    \psaxes
    [
        trigLabels=true,
        labelFontSize=\scriptscriptstyle,
        tickcolor=gray,
        ticksize=-1.5pt 1.5pt,
        xlabelsep=3pt,
        arrowscale=1,
        trigLabelBase=\TrigLabelBase,
        dx=\DeltaX,% must come before xunit to avoid getting a strange output!  
    ]{->}(0,0)(\AxiL,\AxiB)(\AxiR,\AxiT)[$x$,0][$y$,90]
\end{pspicture}


\end{document}

Notes

Compile the code with latex->dvips->ps2pdf.

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