[Tex/LaTex] How to change the tick labels of extra ticks in a loglog plot made with pgfplots

Question

I am trying to make the tick labels of extra ticks of a loglog axis (ie in the MWE, extra x ticks={.5}),consistent with the "log ticks with fixed point", the general format of the label ticks in the example. I have not found a solution.

\documentclass[paper=a4, border=1cm]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.8}

\begin{document}
\begin{tikzpicture}
\begin{loglogaxis}[
grid=both,
width=\textwidth, height=\textwidth,
log ticks with fixed point,
xmin=.005,
xmax =1,
ymin=100,
ymax =200,
extra x ticks={.5}, % how to convert to fixed point tick label ?
ytick={100, 110, 120, 130, 140 , 150, 160, 170, 180 ,190, 200},
legend style={at={(.995,.94)},anchor=east},
]
\addplot [green, ] coordinates {
(.47,50)
(.048, 500)
};
\addplot [blue, ] coordinates {
(.11, 23)
(.0053, 500)
};
\end{loglogaxis}
\end{tikzpicture}
\end{document}

Answer 1

The key is that the default style of the extra ticks is set to log identify minor tick positions=true, which sets the formatting no matter how you set /pgf/number format (which I assume you tried). This option is described on page 268 of the 1.11 manual (is there a reason to use compat=1.8?). Anyway, the fix is to set log identify minor tick positions=false in the extra x tick style:

\documentclass[border=1cm]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.8}

\begin{document}
\begin{tikzpicture}
\begin{loglogaxis}[
grid=both,
width=\textwidth, height=\textwidth,
log ticks with fixed point,
xmin=.005,
xmax =1,
ymin=100,
ymax =200,
extra x ticks={.5}, % how to convert to fixed point tick label ?
extra x tick style={log identify minor tick positions=false},
ytick={100, 110, 120, 130, 140 , 150, 160, 170, 180 ,190, 200},
legend style={at={(.995,.94)},anchor=east},
]
\addplot [green, ] coordinates {
(.47,50)
(.048, 500)
};
\addplot [blue, ] coordinates {
(.11, 23)
(.0053, 500)
};
\end{loglogaxis}
\end{tikzpicture}
\end{document}