It's my first post. I solved it when writing this so I send it anyway in case it helps someone.
When compiled with pdflatex.exe from MiKTeX 2.7 it works. When compiled with pdflatex.exe from MiKTeX 2.9 the fill opacity property of \addplot also compiles without errors but when opened in a pdf reader, the reader returns error: pgf@ca0.5 blablabla.
To fix this problem (I don't know why) you should avoid using packages: pstricks, pst-node, pst-plot, pst-circ.
Here's my corrected code
\documentclass[addressstd,a4paper,10pt]{article}
\usepackage{tikz}
\usepackage{pgfplots}
%\usepackage{pstricks, pst-node, pst-plot, pst-circ}
\begin{document}
\begin{tikzpicture}
\begin{semilogxaxis}
\addplot [black,thick,ybar interval,fill=black,]
coordinates {(22.1,68.9) (44.2,74.4) (88.4,86.5)};
\addlegendentry{one};
\addplot [blue,thick,ybar interval,fill=blue,fill opacity=.5]
coordinates {(22.1,78.9) (44.2,64.4) (88.4,86.5)};
\addlegendentry{two};
\end{semilogxaxis}
\end{tikzpicture}
\end{document}
Do you know why?
;after the legends, and the output is fine when I run in apstrickscompatible way. Which engine are you using? Have you seen http://tex.stackexchange.com/q/8413/15925? – Andrew Swann Apr 08 '14 at 07:03using miktex 2.9 pdflatex (I am using texnic 1.0 to compile)
– Ernesto Apr 10 '14 at 16:55