Adjusting edge and vertex label

Question

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.

Answer 1

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.

Answer 2

A PSTricks solution:

\documentclass{article}

\usepackage{pstricks-add}
\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.

Answer 3

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).