# PGFplots xaxis to use exact values and not scale

I have a graph with values in xaxis as powers of 2. PGFplots automatically changes the x labels. I want it to use the exact values. What option should I use?

\documentclass{article}
\usepackage{pgfplots}
\pagestyle{empty}
\begin{document}
{
1   1
2   3
4   5
8   7
16  7
32  7
64  8
128 9
}\datafile
\begin{tikzpicture}
\begin{axis}
[
title=test
,xlabel=size
,ylabel=Througput
]
\end{axis}
\end{tikzpicture}
\end{document}


-

If you add xtick=data then only the data points are taken as tick values. And you get

Instead you can use the loagrithmic axis for x values and change the base of logarithm to 2 via adding log basis x key.

\documentclass[border=5mm]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.10}
{
1   1
2   3
4   5
8   7
16  7
32  7
64  8
128 9
}\datafile

\begin{document}
\begin{tikzpicture}
\begin{semilogxaxis}
[
title=test
,xlabel=size
,ylabel=Througput,xtick=data,log basis x=2
]

Thank you. I actually tried both the versions. Version 1 has all the x ticks but it automatically scales the xaxis. In version 2 as log axis is used, scaling is even, but the numbers are displayed in powers of 2. So I modified version 1 to include symbolic x coords={1,2,4,8,16,32,64,128} so that it doesn't scale the axis –  arunmoezhi Jul 20 '14 at 19:54