documentclass[10pt]{amsart}
usepackage{tikz}
usepackage{pgfplots}
pgfplotsset{compat=1.11}


begin{document}

hspace*{fill}
begin{tikzpicture}
begin{axis}[width=4in,axis equal image,
          xmax=3,ymax=1.5,
          axis lines=middle,
          restrict y to domain=-1:2,
          enlargelimits,
          axis line style={shorten >=-0.25cm,shorten <=-0.25cm,latex-latex},
          ticklabel style={fill=white},
          extra x ticks={-2,-1,0,1,2},
          %extra x tick style={grid=none}
]

addplot[domain=-2.5:2.5,mark=none,samples=200] {abs(sin(pi(x)))} node[fill=white, below left, yshift=-3pt]{$y=vertsin(pi x)vert$};


end{axis}
end{tikzpicture}
hspace{fill}