Create a ring diagram in TeX

To make it short, I am searching for a 2D variant of this plot How to design a 3D donut pie chart with pgf-plot? Especially the label for each segment are important for my application. I don't need any stylish shading, segments should have constant colour.

I hope someone could help me to create a diagram like this, because i am quite new to LaTeX and the whole package stuff :)

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Something like this: tex.stackexchange.com/a/18105/2552? –  Jake Nov 14 '12 at 16:38
yes, without the "smaller" segments and with lines to the labels –  MrMuh Nov 14 '12 at 16:55

Adapted from How can I produce a 'ring (or wheel) chart' like that on page 88 of the PGF manual?, created using the line

\wheelchart{26/cyan/Corporate,  28/orange/Plastique, 33.5/yellow/Chimique, 12.5/blue!50!red/Rhodia}


\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows}
\begin{document}

% Adjusts the size of the wheel:

% The main macro
\newcommand{\wheelchart}[1]{
% Calculate total
\pgfmathsetmacro{\totalnum}{0}
\foreach \value/\colour/\name in {#1} {
\pgfmathparse{\value+\totalnum}
\global\let\totalnum=\pgfmathresult
}

\begin{tikzpicture}

% Calculate the thickness and the middle line of the wheel

% Rotate so we start from the top
\begin{scope}[rotate=90]

% Loop through each value set. \cumnum keeps track of where we are in the wheel
\pgfmathsetmacro{\cumnum}{0}
\foreach \value/\colour/\name in {#1} {
\pgfmathsetmacro{\newcumnum}{\cumnum + \value/\totalnum*360}

% Calculate the percent value
\pgfmathsetmacro{\percentage}{\value/\totalnum*100}
% Calculate the mid angle of the colour segments to place the labels
\pgfmathsetmacro{\midangle}{-(\cumnum+\newcumnum)/2}

% This is necessary for the labels to align nicely
\pgfmathparse{
(-\midangle<180?"west":"east")
} \edef\textanchor{\pgfmathresult}
\pgfmathsetmacro\labelshiftdir{1-2*(-\midangle>180)}

% Draw the color segments. Somehow, the \midrow units got lost, so we add 'pt' at the end. Not nice...

% Draw the data labels
\draw  [*-,thin] node [append after command={(\midangle:\midradius pt) -- (\midangle:\outerradius + 1ex) -- (\tikzlastnode)}] at (\midangle:\outerradius + 1ex) [xshift=\labelshiftdir*0.5cm,inner sep=0pt, outer sep=0pt, ,anchor=\textanchor]{\name: \pgfmathprintnumber{\percentage}\%};

% Set the old cumulated angle to the new value
\global\let\cumnum=\newcumnum
}

\end{scope}
\end{tikzpicture}
}

% Usage: \wheelchart{<value1>/<colour1>/<label1>, ...}
\wheelchart{26/cyan/Corporate,  28/orange/Plastique, 33.5/yellow/Chimique, 12.5/blue!50!red/Rhodia}

\end{document}

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awsome work! but i have a problem when using \usepackage{ngerman} \usepackage[ngerman]{babel}. do you know how to fix the problem (! Missing { inserted.) ? –  MrMuh Nov 14 '12 at 17:38
@MrMuh: I don't have that problem. What versions of ngerman, babel and tikz are you using? (I'm using v2.5e, v3.8m and v2.10, respectively) –  Jake Nov 14 '12 at 18:01
This is very nice! It definitely belongs into a TikZ or pgfplots library! –  Alexander Nov 14 '12 at 18:24
@Jake: Wow. The most impressive part for me is how the labels are placed! Still trying to figure it out -- Soooooo much still to learn... –  Peter Grill Nov 14 '12 at 19:15
@Jake: I agree with Peter.. that's really a cool approach. This definitely should become a package! –  Claudio Fiandrino Nov 14 '12 at 19:40