# Adjusting edge and vertex label

I am using the following code (thanks to several answers on TeX.Stackexchange) to draw a small bipartite graph:

\documentclass{article}
\usepackage{tkz-berge}
\usetikzlibrary{fit,shapes,arrows}

\definecolor{myblue}{RGB}{80,80,160}
\definecolor{mygreen}{RGB}{80,160,80}

\begin{document}
\begin{figure}
\centering
\begin{tikzpicture}[scale=0.5]
\GraphInit[vstyle=Classic]
\tikzset{VertexStyle/.style =
{shape=circle,fill=mygreen,minimum size = 6pt,inner sep=0pt}
}
\grEmptyPath[Math,x=0,y=0,prefix=d,RA=3,rotation=270]{2}
\tikzset{VertexStyle/.style =
{shape=circle,fill=myblue,minimum size = 6pt,inner sep=0pt}
}
\grEmptyPath[Math,x=6,y=0,prefix=s,RA=3,rotation=270]{2}
\tikzset{EdgeStyle/.style={->,font=\scriptsize}}
\Edge[label = $0.005$](d0)(s0)
\Edge[label = $0.002$](d0)(s1)
\Edge[label = $0.100$](d1)(s1)
\end{tikzpicture}
\caption{graph}
\label{fig:graph}
\end{figure}
\end{document}


which yields

I want to make a few more changes. These are as follows:

1. Move the vertex labels d0 and d1 to the left so that the edges don't cut across them.
2. Move the edge weights so that the numbers are places right above the edge and parallel to the slope of the edge.

Note: I was consulting this manual, but didn't find helpful information regarding my issues. If you can provide a link to a more exhaustive document, it will be really helpful for me in future.

Progress: Added the line \SetUpVertex[Lpos=-180] before defining the vertex style for the left column, and then added \SetUpVertex[Lpos=0] before defining the vertex style for the right column (i.e., the s0 and s1 vertices). That solves the problem I had with vertex label positions.

• It's a bit hard to help you when we don't know which packages you're using. Please provide a full MWE. – A.Ellett May 17 '15 at 21:34
• Sorry about that. Added the packages. – Chthonic Project May 17 '15 at 21:42
• You still haven't provided a MWE. – Svend Tveskæg May 17 '15 at 23:21
• My most sincere apology for not adding a \documentclass line at the top. I am aware of the definition of an MWE, but isn't this nitpicking a bit too much? – Chthonic Project May 18 '15 at 0:17
• Indeed it is. I just wasn't sure you knew what a MWE was since you didn't add the document class. Sorry for that. – Svend Tveskæg May 18 '15 at 0:30

You already solve the difficult part of problem: position of vertex label. The easy part is labels of edges. There you just add option sloped. So, the code of your MWE is:

    \documentclass{article}

\usepackage{tkz-berge}
\usetikzlibrary{fit,shapes,arrows}

\definecolor{myblue}{RGB}{80,80,160}
\definecolor{mygreen}{RGB}{80,160,80}

\usepackage[active,floats,tightpage]{preview}%<-- just to show figure only
\setlength\PreviewBorder{1em}

\begin{document}
\begin{figure}
\centering
\begin{tikzpicture}[scale=0.5]
\GraphInit[vstyle=Classic]
\SetUpVertex[Lpos=-180]
\tikzset{VertexStyle/.style = {shape=circle, fill=mygreen,
minimum size=6pt,inner sep=0pt}
}
\grEmptyPath[Math,x=0,y=0,prefix=d,RA=3,rotation=270]{2}
%
\SetUpVertex[Lpos=0]
\tikzset{VertexStyle/.style = {shape=circle, fill=myblue,
minimum size=6pt, inner sep=0pt}
}
\grEmptyPath[Math,x=6,y=0,prefix=s,RA=3,rotation=270]{2}
\tikzset{EdgeStyle/.style={->,font=\scriptsize,above,sloped,midway}}%<-- new options
\Edge[label = $0.005$](d0)(s0)
\Edge[label = $0.002$](d0)(s1)
\Edge[label = $0.100$](d1)(s1)
\end{tikzpicture}
\caption{graph}
\label{fig:graph}
\end{figure}
\end{document}


In conversion from pdf to jpg are lost transparency of shapes with edge labels, so the picture is a little bit damaged.

• Ah, perfect! But I also want the edge labels to be placed above the line. – Chthonic Project May 17 '15 at 22:37
• no problem, just add option auto into EdgeStyle. I will edit my answer accordingly. – Zarko May 17 '15 at 22:45
• The labels are still poorly placed; they overlap the lines and are not centered between the two relevant dots. – Svend Tveskæg May 17 '15 at 23:21
• In pdf picture the nodes of edge are just fine. This overlapping is caused by conversion from pdf to jpg. Labels are positioned as defined option auto. This can be changed to select option above. I will edit the code and image again ... – Zarko May 17 '15 at 23:36
• Instead of converting, you can take a screenshot of the pdf. – Alenanno May 18 '15 at 0:03

A PSTricks solution:

\documentclass{article}

\usepackage{xfp}

\def\Label(#1)(#2)#3{%
\psline{->}(#1)(#2)
\pcline[linestyle = none, offset = 8pt](#1)(#2)
\ncput*[nrot = :U]{$#3$}}
\def\pointL(#1)#2{%
\psdot[dotstyle = o, fillcolor = green!80!blue](#1)
\uput[180](#1){$#2$}}
\def\pointR(#1)#2{%
\psdot[dotstyle = o, fillcolor = blue!60!red](#1)
\uput[0](#1){$#2$}}

% parameters
\def\width{4}
\def\height{2}

\begin{document}

\begin{pspicture}(-0.5,-0.15)(\fpeval{\width+0.45},\fpeval{\height+0.4})
\pnodes{P}(0,0)(\width,0)(0,\height)(\width,\height)
\Label(P0)(P1){0.100}
\Label(P2)(P1){0.200}
\Label(P2)(P3){0.500}
\pointL(P0){d_{1}}
\pointL(P2){d_{0}}
\pointR(P1){s_{1}}
\pointR(P3){s_{0}}
\end{pspicture}

\end{document}


All you have to do is change the values of the parameters and the drawing will be adjusted accordingly.

• This is impressive! I didn't know about pstricks. I just did a side-by-side comparison of this and tkz-berge, and the edges definitely look neater in this approach. – Chthonic Project May 18 '15 at 4:29

A try with MetaPost and its boxes package, included in a LuaLaTeX program for convenience. (It can be made independent of LuaLaTeX if desired.)

Edit Note that it needs luamplib version 2.10.1 or higher. Previous versions had a bug concerning the vardef macros defined with a suffix (i.e. the @# of the dot@# macro here).

\documentclass[border=2mm]{standalone}
\usepackage{luamplib}
\mplibtextextlabel{enable}
\begin{document}
\begin{mplibcode}
input boxes
color mygreen, myblue;
mygreen = 16/51(red+2green+blue); myblue = 16/51(red+green+2blue);
ahangle := 30; ahlength := 7bp; % Arrowheads stretched: more visible at s1
numeric r, h, v; h = 4cm; v = 2.5cm;
circmargin := 3pt;
vardef dot@#(expr c) =
fill bpath@# withcolor c; drawboxed(@#); draw bpath@#;
enddef;
beginfig(1);
forsuffixes s = d0, d1, s0, s1: circleit.s(""); endfor
s0.c - d0.c = (h, 0); d0.c - d1.c = s0.c - s1.c = (0, v);
forsuffixes i = 0, 1:
dot.d[i](mygreen); dot.s[i](myblue);
drawarrow d[i].e -- s[i].w;
endfor
drawarrow d0.c -- s1.c cutbefore bpath.d0 cutafter bpath.s1;
label.lft("$d_0$", d0.w); label.rt("$s_0$", s0.e);
label.lft("$d_1$", d1.w); label.rt("$s_1$", s1.e);
label.top("$0.005$", .5[d0.c, s0.c]);
label.top("$0.002$", .5[d0.c, s1.c])
rotatedaround (.5[d0.c, s1.c], angle(s1.c-d0.c));
label.top("$0.100$", .5[d1.c, s1.c]);
endfig;
\end{mplibcode}
\end{document}


The dot d0 is centered at the origin, the positions of the other nodes can be changed at will via the h and v parameters, as the dots' radius (value given to the circmargin variable defined in the boxes package).