[Tex/LaTex] TikZ: Replacing the values (labels) on x-axis with names

Question

I managed to create a simple linear plot with pgfplots-manual (chapter 4.5.1)

Now I want to replace the values of x-axis (1,2,3,4) with text, e.g.Test A, Test B, Test C, Test D. How can I do such a configuration?

MWE:

    \documentclass[12pt,ngerman]{article}
    \usepackage{pgfplots}
    \pgfplotsset{width=7cm,compat=1.10}

    \begin{document}

    \begin{tikzpicture}
    \begin{axis}
        [
        xlabel={Test},
        ylabel={Mean}
        ]
    \addplot+[sharp plot] coordinates
    {(0,18.26) (1,21.47) (2,24.58) (3,24.95)};
    \end{axis}
    \end{tikzpicture}

    \end{document}

Answer 1

You have to rename the already existing tick labels. Therefore you define the position of the ticks (one tick for each data point as seen below or ticks in a certain pattern as seen in the commented line) by xtick= and rename their labels by xticklabels=.

% arara: pdflatex

\documentclass[12pt]{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.10}

\begin{document}
\begin{tikzpicture}
    \begin{axis}
        [
        ,width=7cm
        ,xlabel=Test
        ,ylabel=Mean
        ,xtick=data,
       %,xtick={0,1,...,3}
        ,xticklabels={Test A,Test B,Test C,Test D}
        ]
        \addplot+[sharp plot] coordinates
        {(0,18.26) (1,21.47) (2,24.58) (3,24.95)};
    \end{axis}
\end{tikzpicture}
\end{document}