begin{tikzpicture}[scale=3, nodes={
       execute at begin node=$,
       execute at end node=$
     }]
draw[-, thick] (-1,0) -- (1,0) node[above] {};
foreach x/xpar/xtext in {
    -0.8  / | / +,
    -0.6  / | / ,
    -0.4  / | / +,
    -0.2  / | / -,
     0    / | / ,
     .2   / | / -,
     .4   / | / +,
     .6   / | / -,
     .8   / | / +,
}   draw[thick] (x,0pt) node {xpar}  node[below=5pt] {xtext};
end{tikzpicture}

documentclass[tikz,border=3.14mm]{standalone}
begin{document}
begin{tikzpicture}[scale=3, nodes={
       execute at begin node=$,
       execute at end node=$
     }]
draw[-, thick] (-1,0) -- (1,0) node[above] {};
foreach x/xpar/xtext in {
    -0.8  / | / +,
    -0.6  / | / ,
    -0.4  / | / +,
    -0.2  / | / -,
     0    / | / ,
     .2   / | / -,
     .4   / | / +,
     .6   / | / -,
     .8   / | / +,
}   draw[thick] (x,0pt) node {xpar}  node[below=5pt] {xtext};
draw[blue] plot[variable=x,samples=100,domain=-1:1] (x,{0.2*sin((x-0.3)*900)});
end{tikzpicture}
end{document}

documentclass[tikz,border=3.14mm]{standalone}
begin{document}
begin{tikzpicture}[scale=3, nodes={
       execute at begin node=$,
       execute at end node=$
     }]
draw[-, thick] (-1,0) -- (1,0) node[above] {};
foreach x/xpar/xtext in {-0.8,-0.6,...,0.8}
{pgfmathtruncatemacro{y}{sign(sin((x-0.3)*900))}
ifnumy=1
defxtext{+}
else
defxtext{-}
fi
draw (x,-2pt) -- (x,2pt);
node at (x,{-y*5pt}) {xtext};}
draw[blue] plot[variable=x,samples=100,domain=-1:1] (x,{0.2*sin((x-0.3)*900)});
end{tikzpicture}
end{document}

documentclass[tikz,border=7pt]{standalone}
begin{document}
  tikz
    draw[blue](,)foreach~in{+,-,+,-,+,-,+}
      {sin+(,~1)+(0,~-1)node[black,label={[scale=2]~-90:$~$}]{$|$}+(0,0)cos+(,~-1)}
      +(,0)edge[black,latex-](0,);
end{document}