6. LaTeX usage

Asymptote comes with a convenient LaTeX style file asymptote.sty that makes LaTeX Asymptote-aware. Entering Asymptote code directly into the LaTeX source file, at the point where it is needed, keeps figures organized and avoids the need to invent new file names for each figure. Simply add the line \usepackage{asymptote} at the beginning of your file and enclose your Asymptote code within a \begin{asy}...\end{asy} environment. As with the LaTeX comment environment, the \end{asy} command must appear on a line by itself, with no leading spaces or trailing commands/comments.

The sample LaTeX file below, named latexusage.tex, can be run as follows:

latex latexusage
asy latexusage
latex latexusage

or

pdflatex latexusage
asy latexusage
pdflatex latexusage

To switch between using latex and pdflatex you may first need to remove the files latexusage-*, latexusage_.pre, and latexusage.aux.

One can specify width, height, viewportwidth, viewportheight, and attach keyval-style options to the asy environment. The current version (1.06) of asymptote.sty supports the embedding of 3D PRC files, either inline or, using the attach option with the attachfile2 (or older attachfile) LaTeX package, as annotated (but printable) attachments. For many applications, the annotated attachment method tends to be more convenient. The default value of viewportwidth is \the\linewidth for inline 3D figures and 0 for attachments.

If the inline option is given to the asymptote.sty package, inline LaTeX code is generated instead of EPS or PDF files. This makes LaTeX symbols visible to the \begin{asy}...\end{asy} environment. In this mode, Asymptote correctly aligns LaTeX symbols defined outside of \begin{asy}...\end{asy}, but treats their size as zero; an optional second string can be given to Label to provide an estimate of the unknown label size.

Note that if latex is used with the inline option, the labels might not show up in DVI viewers that cannot handle raw PostScript code. One can use dvips/dvipdf to produce PostScript/PDF output (we recommend using the modified version of dvipdf in the Asymptote patches directory, which accepts the dvips -z hyperdvi option).

An excellent tutorial by Dario Teixeira on integrating Asymptote and LaTeX is available at http://dario.dse.nl/projects/asylatex/.

Here now is latexusage.tex:

\documentclass[12pt]{article}

% Use this form to include EPS (latex) or PDF (pdflatex) files:
\usepackage{asymptote}

% Use this form with latex or pdflatex to include inline LaTeX code:
%\usepackage[inline]{asymptote}

% Enable this line to support PDF hyperlinks:
%\usepackage[setpagesize=false]{hyperref}

% Enable this line for PDF attachments with asy environment option attach=true:
%\usepackage[dvips]{attachfile2}

\begin{document}

\begin{asydef}
// Global Asymptote definitions can be put here.
usepackage("bm");
texpreamble("\def\V#1{\bm{#1}}");
// One can globally override the default toolbar settings here:
// settings.toolbar=true;
\end{asydef}

Here is a venn diagram produced with Asymptote, drawn to width 4cm:

\def\A{A}
\def\B{\V{B}}

%\begin{figure}
\begin{center}
\begin{asy}
size(4cm,0);
pen colour1=red;
pen colour2=green;

pair z0=(0,0);
pair z1=(-1,0);
pair z2=(1,0);
real r=1.5;
path c1=circle(z1,r);
path c2=circle(z2,r);
fill(c1,colour1);
fill(c2,colour2);

picture intersection=new picture;
fill(intersection,c1,colour1+colour2);
clip(intersection,c2);

add(intersection);

draw(c1);
draw(c2);

//draw("$\A$",box,z1);              // Requires [inline] package option.
//draw(Label("$\B$","$B$"),box,z2); // Requires [inline] package option.
draw("$A$",box,z1);            
draw("$\V{B}$",box,z2);

pair z=(0,-2);
real m=3;
margin BigMargin=Margin(0,m*dot(unit(z1-z),unit(z0-z)));

draw(Label("$A\cap B$",0),conj(z)--z0,Arrow,BigMargin);
draw(Label("$A\cup B$",0),z--z0,Arrow,BigMargin);
draw(z--z1,Arrow,Margin(0,m));
draw(z--z2,Arrow,Margin(0,m));

shipout(bbox(0.25cm));
\end{asy}
%\caption{Venn diagram}\label{venn}
\end{center}
%\end{figure}

Each graph is drawn in its own environment. One can specify the width
and height to \LaTeX\ explicitly. This 3D example can be viewed
interactively either with Adobe Reader or Asymptote's fast OpenGL-based
renderer. It is often desirable to embed such files as annotated attachments;
this requires the optional \verb+\usepackage{attachfile2}+ package and
the \verb+{attach=true}+ option:
\begin{center}
\begin{asy}[height=4cm,attach=false]
import three;
currentprojection=orthographic(5,4,2);
draw(unitcube,blue);
label("$V-E+F=2$",(0,1,0.5),3Y,blue+fontsize(17));
\end{asy}
\end{center}

One can also scale the figure to the full line width:
\begin{center}
\begin{asy}[width=\the\linewidth]
pair z0=(0,0);
pair z1=(2,0);
pair z2=(5,0);
pair zf=z1+0.75*(z2-z1);

draw(z1--z2);
dot(z1,red+0.15cm);
dot(z2,darkgreen+0.3cm);
label("$m$",z1,1.2N,red);
label("$M$",z2,1.5N,darkgreen);
label("$\hat{\ }$",zf,0.2*S,fontsize(24)+blue);

pair s=-0.2*I;
draw("$x$",z0+s--z1+s,N,red,Arrows,Bars,PenMargins);
s=-0.5*I;
draw("$\bar{x}$",z0+s--zf+s,blue,Arrows,Bars,PenMargins);
s=-0.95*I;
draw("$X$",z0+s--z2+s,darkgreen,Arrows,Bars,PenMargins);
\end{asy}
\end{center}
\end{document}