This is my first question in tex.stackexchange. It might be relatively simple problem but I am having difficulties with the placement of the nodes inside graphics.
The problem is that when I try to compile the code below I get the result which has problem.
\documentclass{standalone}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}[thick,ticks=none,domain=-pi:pi,samples=1000,axis x line=middle,axis y line=none,xlabel={t},xmin=-4,xmax=7,ymax=2,ymin=-2]
\addplot[smooth, color=black] (\x,{sin((9*(deg(x))) )*cos(((deg(x))) )}) node[pos=0.75,pin={carrier wave},thick,inner sep=0pt] {};
\addplot[smooth, color=black] (\x,{cos(((deg(x))) )}) ;
\addplot[smooth, color=black] (\x,{-cos(((deg(x))) )}) node[pos=0.75,pin={envelope wave},thick,inner sep=0pt] {};
\end{axis}
\end{tikzpicture}
\end{document}
It should look like this (look at the position of the pinned text):

Once it was working but now it is not working.

\documentclassending with\end{document}and including only the necessary packages that reproduce the problem. This will help who wants to answer you.:)– Claudio Fiandrino Apr 03 '13 at 10:30carrier waveis not in the correct location? It's important to provide an MWE as @ClaudioFiandrino stated, otherwise we can't determine which options might be interfering with your image. – Mythio Apr 03 '13 at 10:47code\addplot[smooth, color=black] (\x,{sin((9(deg(x))) )cos(((deg(x))) )}) node[pos=0.93,pin=85:{carrier wave},thick] {}; \addplot[smooth, color=black] (\x,{cos(((deg(x))) )}) ; \addplot[smooth, color=black] (\x,{-cos(((deg(x))) )}) node[pos=0.52,pin=10:{envelope wave},thick] {}; – buraker Apr 03 '13 at 10:59