\documentclass{article}
\usepackage[active,tightpage]{preview}
\usepackage{varwidth}
\usepackage{pgfplots}
\begin{document}
\begin{preview}
\begin{varwidth}{\linewidth}
\centering
\begin{tikzpicture}
\begin{axis}[ 
	title = \textbf{Decision Tree},
	xlabel=Number of extracted features, 
	ylabel=Accuracy,
	grid=both,
 	height=5cm, width=8.0cm, 
 	legend pos=south east, 
 	minor tick num = 1,
	xtick={1, 2, 3, 4, 5, 6},
	cycle list={{gray,line width=1.5pt},{black,line width=1.5pt},}
	]
\addplot+[error bars/.cd, x dir=none, x fixed relative=0.5, y dir=both,y explicit relative,]
table[x=features,y=PCA,y error=PCA_conf]{
features	PCA	PCA_conf	BDPC	BDPC_conf
1	0.712323	0.006861	0.709355	0.007779
2	0.731484	0.005784	0.772194	0.007472
3	0.768258	0.007675	0.800581	0.006129
4	0.793161	0.006751	0.802194	0.005311
5	0.802645	0.005431	0.799226	0.005791
6	0.799355	0.005499	0.799290	0.005332
};
\addplot+[error bars/.cd,
x dir=none, x fixed relative=0.5,
y dir=both,y explicit relative,
]
table[x=features,y=BDPC,y error=BDPC_conf]{
features	PCA	PCA_conf	BDPC	BDPC_conf
1	0.712323	0.006861	0.709355	0.007779
2	0.731484	0.005784	0.772194	0.007472
3	0.768258	0.007675	0.800581	0.006129
4	0.793161	0.006751	0.802194	0.005311
5	0.802645	0.005431	0.799226	0.005791
6	0.799355	0.005499	0.799290	0.005332
};
\legend{PCA, Proposed}
\end{axis}
\end{tikzpicture}
\end{varwidth}
\end{preview}
\end{document}
