Sorry for the undetailed title, I didn't know what to call this. How can I draw the image below in TiKz or PSTricks?

Sorry for the undetailed title, I didn't know what to call this. How can I draw the image below in TiKz or PSTricks?

It is recommended to use standalone document class for each diagram and compile it with either latex-dvips-ps2pdf or xelatex. The resulting output is a PDF file that you can import with \includegraphics into your main document.

\documentclass[pstricks,border=3pt]{standalone}
\usepackage{pst-plot,pst-node}
\begin{document}
\begin{pspicture}(-2,-.5)(2,7)
\psaxes[labels=none,ticks=none](0,0)(-2,0)(2,6.5)
\psplot[algebraic,swapaxes]{0}{Pi 2 mul}{-sin(x)}
\pscircle[fillstyle=solid](!0 Pi 2 mul){3pt}
\pcline{->}(!0 Pi 2 div)(!-1 Pi 2 div)
\naput{$r$}
\pcline{->}(1,0)(1,1)
\naput{$x$}
\end{pspicture}
\end{document}

\documentclass[pstricks,border=3pt]{standalone}
\usepackage{pst-plot,pst-node}
\def\f{-sin(x)*1.2^(-2*x)}
\begin{document}
\begin{pspicture}(-2,-.5)(2,7)
\psaxes[labels=none,ticks=none](0,0)(-2,0)(2,6.5)
\psplot[algebraic,swapaxes]{0}{Pi 2 mul}{\f}
\pscircle[fillstyle=solid](!0 Pi 2 mul){3pt}
\pcline{->}(!0 Pi 2 div)(!-.55 Pi 2 div)
\naput{$r$}
\pcline{->}(1,0)(1,1)
\naput{$x$}
\end{pspicture}
\end{document}
-sin (x) is it possible to have a lower amplitude at the beginning?
– Jeel Shah
May 14 '13 at 20:33
An option using TikZ:
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes.arrows}
\begin{document}
\begin{tikzpicture}[thick]
\draw (0,0) -- +(0,-7);
\draw (-1.5,-7) -- (1.5,-7);
\draw (0,-7) .. controls (-2,-5) and (1,-2) .. (0,-2pt);
\begin{scope}[myarrow/.style={single arrow,draw,inner sep=2pt,text width=#1,single arrow head extend=2.5pt,thin}]
\node[myarrow=5pt,label=below:$r$,xscale=-1] at (-0.3,-5) {};
\node[myarrow=12pt,label=above:$x$,rotate=90] at (0.8,-6.5) {};
\end{scope}
\fill[white,draw=black] (0,0) circle[radius=4pt];
\end{tikzpicture}
\end{document}

controlssyntax from this one http://tex.stackexchange.com/questions/43739/how-to-create-candle-symbol-in-latex – percusse May 14 '13 at 20:12