# Drawing lines to the correct circle

I have the following code

\def\aes{in*0.75}%%
\begin{tikzpicture}[scale=0.34mm]
\coordinate (A) at (0,0);
\coordinate (B) at ($(A)+(30:4\aes)$);
\coordinate (C) at ($(B)+(-90:2.5\aes)$);

\draw[line width=2pt,gray!60,postaction={draw,black,dashed,line width=1.4pt}] (A) circle (\aeRadiusA);

\coordinate (A1a) at ($(A)+(-20:\aeRadiusA*0.75)$);
\coordinate (C1a) at ($(C)+(90+20:\aeRadiusC*0.75)$);
\coordinate (A1b) at ($(A1a)+(3pt,2pt)$);
\coordinate (C1b) at ($(C1a)+(0pt,-2pt)$);

\coordinate (A2a) at ($(A)+(30:\aeRadiusA*0.65)$);
\coordinate (B2a) at ($(B)+(140:\aeRadiusB*0.65)$);
\coordinate (A2b) at ($(A2a)+(15pt,4pt)$);
\coordinate (B2b) at ($(B2a)+(-4pt,3pt)$);

\begin{scope}[rotate=280]
\fill[red!20] (B2a) circle (4pt);
\foreach \x in {-3,...,5}{
\draw[blue,shorten >= rand*15] (B2a) -- (rand*\x:3);
}
\fill[blue] (B2a) circle(2pt);
\end{scope}

\node[anchor=north west] at (A) {9-graph};
\node                    at (B) {4-graph};
\node                    at (C) {5-graph};
\end{tikzpicture}


which draws some lines from circle B to spots in circle A. I am unsure how to make it so that the lines are drawn to points inside circle C. Does anyone know how I would go about this?

As per request, the following image is what I want

and is achieved with

\coordinate (A1a) at ($(A)+(-20:\aeRadiusA*0.75)$);
\coordinate (C1a) at ($(C)+(90+20:\aeRadiusC*0.75)$);
\coordinate (A1b) at ($(A1a)+(3pt,2pt)$);
\coordinate (C1b) at ($(C1a)+(0pt,-2pt)$);
\coordinate (C1c) at ($(C1b)+(5pt,-2pt)$);
\coordinate (C1d) at ($(C1c)+(10pt,8pt)$);
\coordinate (C1e) at ($(C1d)+(10pt,8pt)$);
\coordinate (C1f) at ($(C1e)+(-5pt,-2pt)$);
\coordinate (C1g) at ($(C1e)+(-45pt,-20pt)$);

\coordinate (A2a) at ($(A)+(30:\aeRadiusA*0.65)$);
\coordinate (B2a) at ($(B)+(140:\aeRadiusB*0.65)$);
\coordinate (A2b) at ($(A2a)+(15pt,4pt)$);
\coordinate (B2b) at ($(B2a)+(-4pt,3pt)$);

\begin{scope}[rotate=100]
\fill[red!20] (B2a) circle (4pt);

\draw[blue] (B2a) -- (C1a);
\draw[red] (B2a)  -- (C1b);
\draw[blue] (B2a) -- (C1c);
\draw[red] (B2a)  -- (C1d);
\draw[blue] (B2a) -- (C1e);
\draw[red] (B2a)  -- (C1f);
\draw[blue] (B2a)  -- (C1g);
\fill[red] (B2a) circle(2pt);
\end{scope}


As you can see, the lines are hard-coded and not what I want.

• It would be great to add some pictures to show what you want to achieve. Additionally, please tell us what you tried to solve the problem. – JF Meier Dec 1 '15 at 13:10
• @JFMeier See the edit – RElon Dec 1 '15 at 13:24
• @RElon Welcome to TeX.SX! Please make your code compilable (if possible), or at least complete it with \documentclass{...}, the required \usepackage's, \begin{document}, and \end{document}. That may seem tedious to you, but think of the extra work it represents for TeX.SX users willing to give you a hand. Help them help you: remove that one hurdle between you and a solution to your problem. – AboAmmar Dec 1 '15 at 13:38
• Ah come on what else do you need ? The code is there... – percusse Dec 1 '15 at 14:10
• BTW, you can use \newlength{\aes} and \setlength{\aes}{0.75in} which is how 4\aes is normally implemented. – John Kormylo Dec 1 '15 at 14:17

If it is just about drawing the lines from one fixed point to a number of other points with two alternating colors you can do the following:

\documentclass[tikz, border=5mm]{standalone}

\begin{document}
\begin{tikzpicture}
\foreach [count=\i] \x in {a,...,g} {
% use a mod() for swapping between red and blue
\pgfmathparse{mod(\i, 2) ? "red" : "blue"}
% draw from fixed point to point in foreach with color determined by mod()
\draw [\pgfmathresult] (B2a) -- (C1\x);
}
\end{tikzpicture}
\end{document}