\documentclass{article}
\usepackage[active,tightpage]{preview}
\usepackage{varwidth}
\usepackage{pgfplots}
\begin{document}
\begin{preview}
\begin{varwidth}{18cm}
\centering
\begin{tabular}{cc}
\multicolumn{2}{c}{\textbf{
Occupancy
 Dataset}} \\

\begin{tikzpicture}
\begin{axis}[ 
	title = \textbf{Decision Tree},
	ylabel=Accuracy,
	grid=both,
 	height=5cm, width=8.0cm, 
 	legend pos=south east, 
 	minor tick num = 1,
	xtick={1, 2, 3, 4, 5},
	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	0.932363	0.000804	0.932363	0.000804
2	0.983368	0.000358	0.983368	0.000358
3	0.988514	0.000329	0.989157	0.000375
4	0.989686	0.000368	0.989460	0.000405
5	0.989614	0.000371	0.989585	0.000367
};
\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	0.932363	0.000804	0.932363	0.000804
2	0.983368	0.000358	0.983368	0.000358
3	0.988514	0.000329	0.989157	0.000375
4	0.989686	0.000368	0.989460	0.000405
5	0.989614	0.000371	0.989585	0.000367
};
\end{axis}
\end{tikzpicture}
&
\begin{tikzpicture}
\begin{axis}[ 
	title = \textbf{k-NN},
	grid=both,
 	height=5cm, width=8.0cm, 
 	legend pos=south east, 
 	minor tick num = 1,
	xtick={1, 2, 3, 4, 5},
	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	0.928376	0.000699	0.928376	0.000699
2	0.985380	0.000305	0.985380	0.000305
3	0.988199	0.000318	0.985994	0.000315
4	0.988271	0.000314	0.985994	0.000315
5	0.988271	0.000314	0.988271	0.000314
};
\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	0.928376	0.000699	0.928376	0.000699
2	0.985380	0.000305	0.985380	0.000305
3	0.988199	0.000318	0.985994	0.000315
4	0.988271	0.000314	0.985994	0.000315
5	0.988271	0.000314	0.988271	0.000314
};
\end{axis}
\end{tikzpicture}
\\
\begin{tikzpicture}
\begin{axis}[ 
	title = \textbf{Linear Discriminant},
	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},
	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	0.934510	0.000523	0.934510	0.000523
2	0.974856	0.000656	0.974856	0.000656
3	0.975662	0.000603	0.986040	0.000638
4	0.986662	0.000575	0.987912	0.000346
5	0.987770	0.000299	0.987770	0.000299
};
\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	0.934510	0.000523	0.934510	0.000523
2	0.974856	0.000656	0.974856	0.000656
3	0.975662	0.000603	0.986040	0.000638
4	0.986662	0.000575	0.987912	0.000346
5	0.987770	0.000299	0.987770	0.000299
};
\end{axis}
\end{tikzpicture}
&
\begin{tikzpicture}
\begin{axis}[ 
	title = \textbf{Naive Bayes},
	xlabel=Number of extracted features, 
	grid=both,
 	height=5cm, width=8.0cm, 
 	legend pos=south east, 
 	minor tick num = 1,
	xtick={1, 2, 3, 4, 5},
	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	0.948804	0.000500	0.948804	0.000500
2	0.958344	0.000609	0.958344	0.000609
3	0.958418	0.000692	0.960911	0.000578
4	0.959892	0.000557	0.960680	0.000513
5	0.960631	0.000476	0.960631	0.000476
};
\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	0.948804	0.000500	0.948804	0.000500
2	0.958344	0.000609	0.958344	0.000609
3	0.958418	0.000692	0.960911	0.000578
4	0.959892	0.000557	0.960680	0.000513
5	0.960631	0.000476	0.960631	0.000476
};
\legend{PCA, Proposed}
\end{axis}
\end{tikzpicture}
\end{tabular}
\end{varwidth}
\end{preview}
\end{document}
