[Tex/LaTex] How to make all nodes same size in mindmap

mindmapsnodestikz-pgf

Is there a way to force all the nodes in a mindmap to have the same size regardless of their hierarchy in the tree?

enter image description here

\begin{figure}\label{fig:HadoopVersion}
    \centering
    \begin{tikzpicture}[concept color=green!50!black,text=white,yscale=0.9,xscale=1.3]
    %level 1/.append style={level distance=4.5cm,sibling angle=90}]
    %level 2/.append style={level distance=3cm,sibling angle=45}]
    \node [concept]{0.24} % root
    child { node [concept] {0.23}
       child [concept color=black!50!white,grow=left] {node [concept] {3.0.0}}
       child [grow=down]{ node [concept] {0.22}
          child [concept color=black!50!white,grow=left] {node [concept,scale=0.9] {0.22.1}
         child {node [concept] {2.0.0}}
          }
          child [grow=down]{ node [concept] (021) {0.21}
         child { node [concept] {0.20}
            child [concept, grow=right, level distance=2cm] {node[concept] {0.20.2}
               child [concept color=black!50!white,grow=up] {node [concept,scale=0.7] (app){0.20.2 app}}
               child [concept color=red!50!black,grow=260,level distance=2cm] {node [concept] {MapR}}
               child [concept color=black!50!white,grow=right] {node [concept,scale=0.6] (yahoo) {0.20.200 Y!}
              child [concept color=green!50!black,grow=up, level distance=2cm] {node [concept,scale=0.8] {0.20.203}
                 child [concept color=red!50!black,grow=60, level distance=2cm]{node [concept,scale=0.6] {0.20.203 Azure}}
                 child [grow=120]{node [concept,scale=0.8] (205) {0.20.205}
                child [grow=up]{node [concept] {1.0.0}}
                 }
              }
               }
               child [concept color=red!50!black,grow=300, level distance=2cm] {node [concept, scale=0.8] (chd3) {CDH3}}
            }
            child [grow=240, level distance=3cm] { node [concept] {0.20.1}
               child [concept color=red!50!black,grow=left, level distance=2cm] {node [concept,scale=0.6] (ibm) {0.20.1 IBM}}
               child [concept color=red!50!black,grow=120] {node [concept,scale=0.6] {0.20.1 Green}
              child [concept color=black!50!white,grow=right, level distance=2cm] {node [concept] (eol) {EOL}}
               }
            }
            child [grow=down] { node [concept] {0.19}
               child { node [concept] {0.18}
              child { node [concept] {Old}}
               }
            }
         }
          }
       }
    };
    \begin{pgfonlayer}{background}
       \path (021) to [circle connection bar switch color=from (green!50!black) to (green!50!black)] (app);
       \path (205) to [circle connection bar switch color=from (green!50!black) to (black!50!white)] (app);
       \path (chd3) to [circle connection bar switch color=from (red!50!black) to (black!50!white)] (yahoo);
       \path (chd3) to [circle connection bar switch color=from (red!50!black) to (black!50!white)] (app);
       \path (ibm) to [circle connection bar switch color=from (red!50!black) to (black!50!white)] (eol);
       \path (eol) to [circle connection bar switch color=from (black!50!white) to (black!50!white)] (app);
    \end{pgfonlayer}
    \end{tikzpicture}
    \caption[Apache Hadoop Project versioning]{Apache Hadoop Project versioning in Spring 2013. Hadoop Apache releases are depicted in \fcolorbox{green!50!black}{green!50!black}{\textcolor{white}{green}} while teh commercial ones are \fcolorbox{red!50!black}{red!50!black}{\textcolor{white}{red}}. The \fcolorbox{white!50!black}{white!50!black}{\textcolor{white}{gray}} nodes stand for non official releases}
    \end{figure}

Best Answer

You could modify the style of every concept:

\tikzset{every concept/.style={minimum size=2cm, text width=2cm}}

Computer science mindmap example with several levels from the manual, with this change, resulting in the same size for all concept nodes, if the text doesn't blow it up:

mindmap example

% Author: Till Tantau
% Source: The PGF/TikZ manual
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{mindmap,trees}
% Here we change the style for all concepts: (Stefan K.)
\tikzset{every concept/.style={minimum size=2cm, text width=2cm}}
\begin{document}
\pagestyle{empty}
\begin{tikzpicture}
  \path[mindmap,concept color=black,text=white]
    node[concept] {C. Science}
    [clockwise from=0]
    child[concept color=green!50!black] {
      node[concept] {practical}
      [clockwise from=90]
      child { node[concept] {algorithms} }
      child { node[concept] {data structures} }
      child { node[concept] {pro\-gramming languages} }
      child { node[concept] {software engineer\-ing} }
    }  
    child[concept color=blue] {
      node[concept] {applied}
      [clockwise from=-30]
      child { node[concept] {databases} }
      child { node[concept] {WWW} }
    }
    child[concept color=red] { node[concept] {technical} }
    child[concept color=orange] { node[concept] {theoretical} };
\end{tikzpicture}
\end{document}