\begin{tikzpicture}
\begin{axis}[
	name=plot1,
	axis lines*=middle,
	enlargelimits = false,
	clip=false,
	scale only axis,
	width=0.7\textwidth,
	height=0.2\textwidth,
	ymin=-1.3,
	ymax=1.3,
	xmin=0,
	xmax=11,
	axis line style={->,>=stealth},
	xlabel={\small $n$},
	ylabel={\small $h[n]$},
	every axis x label/.style={
		at={(ticklabel* cs:1)},
		xshift=0.2cm,
		anchor=north,
	},
	every axis y label/.style={
	at={(ticklabel* cs:0.8)},
	anchor=south,
	xshift=0.6cm,
	},
	ytick=\empty,
	xtick=\empty,
	every outer y axis line/.append style={white!15!black},
	every y tick label/.append style={font=\color{white!15!black}},
	legend style={draw=white!15!black,fill=white,legend cell align=left}]
	\pgfmathsetseed{99}
	\addplot[ycomb, blue2, mark=*, fill=white, mark options={scale=0.75, fill=white}, line width=1pt, domain=0:10, samples=6] {0.5*pretty_func(x)};
	\pgfmathsetseed{99}
	\addplot[ycomb, red2, mark=*, fill=white, mark options={scale=0.75, fill=white}, line width=1pt, domain=1:9, samples=5] {0.5*pretty_func(x)};
	
\end{axis}

\pgfmathsetseed{99}
\begin{axis}[
	name=plot2,
	at=(plot1.below south east), anchor=above north east,
	axis lines*=middle,
	enlargelimits = false,
	clip=false,
	scale only axis,
	width=0.7\textwidth,
	height=0.2\textwidth,
	ymin=-1.3,
	ymax=1.3,
	xmin=0,
	xmax=6,
	axis line style={->,>=stealth},
	xlabel={\small $n$},
	ylabel={\small {\color{blue2} $e_1[n] = h_1[2n]$}},
	every axis x label/.style={
		at={(ticklabel* cs:1)},
		xshift=0.2cm,
		anchor=north,
	},
	every axis y label/.style={
	at={(ticklabel* cs:0.8)},
	anchor=south,
	xshift=1.2cm,
	},
	ytick=\empty,
	xtick=\empty,
	every outer y axis line/.append style={white!15!black},
	every y tick label/.append style={font=\color{white!15!black}},
	legend style={draw=white!15!black,fill=white,legend cell align=left}]
	\addplot[ycomb, blue2, mark=*, fill=white, mark options={scale=0.75, fill=white}, line width=1pt, domain=0:5, samples=6] {0.5*pretty_func(2*x)*(mod(2*x, 2) == 0)};
\end{axis}

\pgfmathsetseed{99}
\begin{axis}[
	name=plot3,
	at=(plot2.below south east), anchor=above north east,
	axis lines*=middle,
	enlargelimits = false,
	clip=false,
	scale only axis,
	width=0.7\textwidth,
	height=0.2\textwidth,
	ymin=-1.3,
	ymax=1.3,
	xmin=0,
	xmax=6,
	axis line style={->,>=stealth},
	xlabel={\small $n$},
	ylabel={\small {\color{red2} $e_2 = h_2[2n]$}},
	every axis x label/.style={
		at={(ticklabel* cs:1)},
		xshift=0.2cm,
		anchor=north,
	},
	every axis y label/.style={
	at={(ticklabel* cs:0.8)},
	anchor=south,
	xshift=1.2cm,
	},
	ytick=\empty,
	xtick=\empty,
	every outer y axis line/.append style={white!15!black},
	every y tick label/.append style={font=\color{white!15!black}},
	legend style={draw=white!15!black,fill=white,legend cell align=left}]
	\addplot[ycomb, red2, mark=*, fill=white, mark options={scale=0.75, fill=white}, line width=1pt, domain=0:5, samples=6] {0.5*pretty_func(2*x+1)*(mod(2*x+1, 2) == 1)};
\end{axis}
\end{tikzpicture}
