parallel lines in tikz multigraph

Question

I am trying to make a multi graph, but the edges all overlap one another. This question has already been asked but I have not been able to find a solution that will work for the format I am using.

I have the following code so far:

\begin{tikzpicture}[scale=2,vertex/.style={circle, fill=black!30, draw, minimum size=.3cm, inner sep=0pt}, 
    arc1/.style={draw=red,line width=1.5pt}, 
    arc2/.style={draw=blue,line width=1.5pt},
    arc3/.style={draw=orange,line width=1.5pt},
    arc4/.style={draw=purple,line width=1.5pt},
    arc5/.style={draw=green,line width=1.5pt}]
    \foreach [count=\i] \coord in {(0,0), (1,1), (-1,1), (1,2), (-1,2)}{
        \node[vertex] (p\i) at \coord {\i};
    }

    \foreach [count=\r] \row in {{0,1,0,0,0}, {1,0,0,1,0}, {0,0,0,0,0}, {0,1,0,0,0}, {0,0,0,0,0}}{
        \foreach [count=\c] \cell in \row{
            \ifnum\cell=1%
            \draw[arc1] (p\r) edge (p\c);
            \fi
        }
    }
    \foreach [count=\r] \row in {{0,0,1,0,0}, {0,0,0,0,0}, {1,0,0,0,1}, {0,0,0,0,0}, {0,0,1,0,0}}{
        \foreach [count=\c] \cell in \row{
            \ifnum\cell=1%
            \draw[arc2] (p\r) edge (p\c);
            \fi
        }
    }
    \foreach [count=\r] \row in {{0,1,0,0,0}, {1,0,1,0,0}, {0,0,1,0,1}, {0,0,0,0,0}, {0,0,1,0,0}}{
        \foreach [count=\c] \cell in \row{
            \ifnum\cell=1%
            \draw[arc3] (p\r) edge (p\c);
            \fi
        }
    }
    \foreach [count=\r] \row in {{0,0,1,0,0}, {0,0,1,1,0}, {1,1,0,0,0}, {0,1,0,0,0}, {0,0,0,0,0}}{
        \foreach [count=\c] \cell in \row{
            \ifnum\cell=1%
            \draw[arc4] (p\r) edge (p\c);
            \fi
        }
    }
    \foreach [count=\r] \row in {{0,1,0,0,0}, {1,0,1,0,0}, {0,1,0,0,1}, {0,0,0,0,1}, {0,0,1,1,0}}{
        \foreach [count=\c] \cell in \row{
            \ifnum\cell=1%
            \draw[arc5] (p\r) edge (p\c);
            \fi
        }
    }
    \end{tikzpicture}

I just need each coloured edge to be visible. I am sure it is a simple change to the line arc1/.style={draw=red,line width=1.5pt}, but everything that I have tried will not work. Any help will be much appreciated.

Answer 1

You can bend the arcs, each color with a different curvature, by adding

bend left=...some number...

to the arc/.style definitions. Note that you cannot use straight lines (curvature=0), since you have arcs of the same color from A to B and from B to A, of which probably both should remain visible.

\documentclass[border=2pt]{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[scale=2,vertex/.style={circle, fill=black!30, draw, minimum size=.3cm, inner sep=0pt}, 
    arc1/.style={draw=red,line width=1.5pt,bend left=10}, % <<<<<<<<<<<
    arc2/.style={draw=blue,line width=1.5pt,bend left=15}, % <<<<<<<<<<<
    arc3/.style={draw=orange,line width=1.5pt,bend left=20}, % <<<<<<<<<<<
    arc4/.style={draw=purple,line width=1.5pt,bend left=25}, % <<<<<<<<<<<
    arc5/.style={draw=green,line width=1.5pt,bend left=5}] % <<<<<<<<<<<
    \foreach [count=\i] \coord in {(0,0), (1,1), (-1,1), (1,2), (-1,2)}{
        \node[vertex] (p\i) at \coord {\i};
    }

    \foreach [count=\r] \row in {{0,1,0,0,0}, {1,0,0,1,0}, {0,0,0,0,0}, {0,1,0,0,0}, {0,0,0,0,0}}{
        \foreach [count=\c] \cell in \row{
            \ifnum\cell=1%
            \draw[arc1] (p\r) edge (p\c);
            \fi
        }
    }
    \foreach [count=\r] \row in {{0,0,1,0,0}, {0,0,0,0,0}, {1,0,0,0,1}, {0,0,0,0,0}, {0,0,1,0,0}}{
        \foreach [count=\c] \cell in \row{
            \ifnum\cell=1%
            \draw[arc2] (p\r) edge (p\c);
            \fi
        }
    }
    \foreach [count=\r] \row in {{0,1,0,0,0}, {1,0,1,0,0}, {0,0,1,0,1}, {0,0,0,0,0}, {0,0,1,0,0}}{
        \foreach [count=\c] \cell in \row{
            \ifnum\cell=1%
            \draw[arc3] (p\r) edge (p\c);
            \fi
        }
    }
    \foreach [count=\r] \row in {{0,0,1,0,0}, {0,0,1,1,0}, {1,1,0,0,0}, {0,1,0,0,0}, {0,0,0,0,0}}{
        \foreach [count=\c] \cell in \row{
            \ifnum\cell=1%
            \draw[arc4] (p\r) edge (p\c);
            \fi
        }
    }
    \foreach [count=\r] \row in {{0,1,0,0,0}, {1,0,1,0,0}, {0,1,0,0,1}, {0,0,0,0,1}, {0,0,1,1,0}}{
        \foreach [count=\c] \cell in \row{
            \ifnum\cell=1%
            \draw[arc5] (p\r) edge (p\c);
            \fi
        }
    }
    \end{tikzpicture}
\end{document}