[texhax] Drawing colored pie chart in KOMA-Class scrreprt (preferably without manually installing pgf-pie

[Suresh Govindachar]

> On Fri, Mar 21, 2014 at 5:02 PM, Pascal <pascal.bernhard at belug.de> asked:

[for a simple, quick way to add a 2-dimensional pie chart with colors 
without having to install pgf-pie]:

   > The first example works
   > (http://www.texample.net/tikz/examples/pie-chart/), but I'm
   > totally at a loss about how get colors into the pie chart.
   > This basically does the trick, I do not aspire to fancy stuff
   > like a drawn out slice, but colors I definitively would like
   > to see.
   [...]
   > I should mention that in my case the pie chart is supposed to
   > show that the markets is carved up by two companies, one
   > having a 69 % market share, the other 29 %, which leaves 2 %
   > for various other tiny firms.  I'm not sure whether I could
   > modify the example above quite easily to fit my needs, so any
   > help here would also be higly appreciated.

Here's a simple tweak to that example to get colors and to illustrate 
your particular "69-29-2" example:

% Pie chart
% Original Author: Robert Vollmert
% Modified to illustrate coloring the slices by Suresh Govindachar
%
\documentclass{article}
\usepackage{calc}
\usepackage{ifthen}
\usepackage{tikz}
\begin{document}

\newcommand{\slice}[5]{
   \pgfmathparse{0.5*#1+0.5*#2}
   \let\midangle\pgfmathresult

   % slice
   \draw[thick,fill=#5] (0,0) -- (#1:1) arc (#1:#2:1) -- cycle;

   % outer label
   \node[label=\midangle:#4] at (\midangle:1) {};

   % inner label
   \pgfmathparse{min((#2-#1-10)/110*(-0.3),0)}
   \let\temp\pgfmathresult
   \pgfmathparse{max(\temp,-0.5) + 0.8}
   \let\innerpos\pgfmathresult
   \node at (\midangle:\innerpos) {#3};
}

\begin{tikzpicture}[scale=3]

\newcounter{a}
\newcounter{b}
\foreach \p/\t/\c in
%
% original example with color added %   {20/type A/green!20!white,
% original example with color added %   4/type B/green!80!white,
% original example with color added %   11/type C/yellow!60!black,
% original example with color added %   49/type D/blue!40!white,
% original example with color added %   16/other/red!40!white}
%
% following is for OP's needs:
                   { 69/Big Company/green!80!black,
                     29/Start Up/blue!40!white,
                      2/Tiny Firms/yellow!30!white}
   {
     \setcounter{a}{\value{b}}
     \addtocounter{b}{\p}
     \slice{\thea/100*360}
           {\theb/100*360}
           {\p\%}{\t}{\c}
   }
\end{tikzpicture}

   From the TikZ document:  The color green!20!white means 20\%
   green and 80\% white mixed together. Such color expression are
   possible since TikZ uses Uwe Kern's xcolor package, see the
   documentation of that package for details on color expressions.

\end{document}