\documentclass[11pt]{article}
% Call this LaTeX file with pdflatex MakePic.tex or
% lualatex MakePic.tex to generate a PDF file MakePic.pdf 
% then you can include the pdf files (much faster)

\usepackage{pgfplots}
\usepackage{tikz,amsmath,siunitx}
\usetikzlibrary{arrows,snakes,backgrounds,patterns,matrix,shapes,fit,calc,shadows,plotmarks}
\usepackage[graphics,tightpage,active]{preview}
\PreviewEnvironment{tikzpicture}
%\PreviewEnvironment{equation}
%\PreviewEnvironment{equation*}
%\newlength{\imagewidth}
%\newlength{\imagescale}
\newlength{\figureheight} 
\newlength{\figurewidth}

\pagestyle{empty}
\thispagestyle{empty}
\begin{document}

%\setlength\figureheight{0.6\textwidth} 
%\setlength\figurewidth{0.8\textwidth}
%\setlength\figureheight{0.6\textwidth} 
\setlength\figurewidth{12cm}
\input Sin2.tikz

\end{document}