documentclass[10pt]{book}
usepackage[paperheight=9in,paperwidth=6in,includehead,includefoot,top=0.5in,bottom=0.5in,outer=0.5in,inner=0.75in]{geometry}

usepackage{amsfonts}
usepackage{amsmath}
usepackage{pgfplots}
pgfplotsset{compat=1.8}
usepackage{siunitx}
usepackage{nicefrac}
usepackage{tikz}
usepgfplotslibrary{groupplots}
usetikzlibrary{arrows}
usepackage{amsthm}
usepackage{amssymb}
usepackage{mathrsfs}
usepackage[numbers]{natbib}
numberwithin{equation}{section}
usepackage{txfonts}
usepackage{hyphenat}
usepackage[overload]{textcase} % Otherwise $p_t$ gets capitalized
                                % into $P_T$ in chapter headings,
                                % which is not desirable
usepackage[colorlinks=true,pdfstartview=FitV,linkcolor=black,citecolor=black,urlcolor=black,plainpages=false,pdfpagelabels]{hyperref}
usepackage[fit]{truncate}
usepackage[toctitles]{titlesec}
usepackage{makeidx}
makeindex
usepackage{url}
usepackage{tocbibind}


begin{tikzpicture}
begin{groupplot}[]
nextgroupplot[declare function ={fy(x)=sin(x+rand*100)^2;}]
begin{axis} [
xmin=-720, xmax=720,
width=10cm, height=10cm,
tick style=black,
clip mode=individual,
x axis line style={opacity=0},
y axis line style={opacity=0},
ticks=none
]
end{axis}

addplot [
ultra thick,
smooth,
tension=1,
samples=30,
domain=-720:720
] {fy(x)};

draw[latex-latex, xshift=-0.5cm] ({rel axis cs:0,0}|-{rel axis cs:0,0}) -- ({rel    axis cs:0,0}|-{rel axis cs:0,1}) node[left, pos=0.5] {$h$};


end{tikzpicture}

! Package pgfplots Error: Sorry, nested axis environments are not supported. Pl
ease move the inner axis environment below end{axis} and use alignment options
 (for example named nodes, see manual) to place it at the desired position.

See the pgfplots package documentation for explanation.
Type  H <return>  for immediate help.
 ...

l.43 ]

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