[Tex/LaTex] Shading a Region Between Two Dashed Lines

tikz-pgf

I have drawn an axis with two dashed vertical lines:

    \begin{tikzpicture}
\begin{axis}[
    axis x line=middle, 
    axis y line=middle, 
    ymin=-6, ymax=6, ytick={1,3,5,-1,-3,-5}, ylabel=$y$, 
    xmin=-2.3, xmax=2.3, xtick={-1,-2,1,2}, xlabel=$x$
    ]
    \pgfplotsinvokeforeach{-1, 1}{
      \draw[dashed,color=red] ({rel axis cs: 0,0} -| {axis cs: #1, 0}) -- ({rel axis cs: 0,1} -| {axis cs: #1, 0});};
     \addplot[red, mark=*] coordinates {(1,1)};
     \addplot[red, mark=*] coordinates {(-1,1)};
\end{axis}
\end{tikzpicture}

I would like to shade the region between the dashed lines.

Best Answer

Here's another possibility (different from what has been suggested in comments) using \closedcycle; the axis on top=true option causes the axis to be typeset on top of the filling:

\documentclass{article}
\usepackage{pgfplots}

\begin{document}

\begin{tikzpicture}
\begin{axis}[
    axis on top=true,
    axis x line=middle, 
    axis y line=middle, 
    ymin=-6, ymax=6, ytick={1,3,5,-1,-3,-5}, ylabel=$y$, 
    xmin=-2.3, xmax=2.3, xtick={-1,-2,1,2}, xlabel=$x$
    ]
\addplot[fill=cyan,domain=-1:1,draw=none] {6} \closedcycle;
\addplot[fill=cyan,domain=-1:1,draw=none] {-6} \closedcycle;
    \pgfplotsinvokeforeach{-1, 1}{
      \draw[dashed,color=red] ({rel axis cs: 0,0} -| {axis cs: #1, 0}) -- ({rel axis cs: 0,1} -| {axis cs: #1, 0});};
     \addplot[red, mark=*] coordinates {(1,1)};
     \addplot[red, mark=*] coordinates {(-1,1)};
\end{axis}
\end{tikzpicture}
\end{document}

enter image description here

Related Solutions

[Tex/LaTex] Shading a region between two polar curves

You could use intersection segments:

\documentclass{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.15}% <- added!!
\usepgfplotslibrary{fillbetween}% <- changed
\begin{document}
\begin{tikzpicture}
\begin{axis}[grid = both,
    set layers% <- added
]
    % Outer curve
    \addplot [data cs=polar, domain=0:360, samples=180, black,
        line width=1pt, smooth,
        name path=outer
        ](x, {1.5+cos(x)});
    % Inner curve
    \addplot [data cs=polar, domain=0:360, samples=180, green,
        line width=1pt, smooth,
        name path=inner
        ](x, 1.5);
    % Filling
    \begin{pgfonlayer}{axis background}
      \fill [orange!30,
          intersection segments={
            of=inner and outer,
            sequence={L0--L1--R1[reverse]--R0[reverse]}
          }];
    \end{pgfonlayer}
\end{axis}
\end{tikzpicture} 
\end{document}

Result:

Example showing the segments:

\documentclass{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.15}% <- added!!
\usepgfplotslibrary{fillbetween}% <- changed
\begin{document}
\begin{tikzpicture}
\begin{axis}[grid = both,
    set layers% <- added
]
    % Outer curve
    \addplot [data cs=polar, domain=0:360, samples=180, black,
        line width=1pt, smooth,
        name path=outer
        ](x, {1.5+cos(x)});
    % Inner curve
    \addplot [data cs=polar, domain=0:360, samples=180, green,
        line width=1pt, smooth,
        name path=inner
        ](x, 1.5);
    % Filling
    \begin{pgfonlayer}{axis background}
        \fill [orange!30,
            intersection segments={
              of=inner and outer,
              sequence={L0--L1--R1[reverse]--R0[reverse]}
            }];
    \end{pgfonlayer}
\end{axis}
% Showing the segments
\begin{scope}[line width=2pt,->,font=\bfseries]
    \foreach[count=\i from 0] \c in {green,orange,purple}{
        \edef\temp{\noexpand\draw [\c,
            intersection segments={of=inner and outer,sequence={L\i}}]node[left]{L\i};}
        \temp}
     \foreach[count=\i from 0] \c in {blue,gray,yellow}{
         \edef\temp{\noexpand\draw [\c,
            intersection segments={of=inner and outer,sequence={R\i}}]node[right]{R\i};}
         \temp}
 \end{scope}
\end{tikzpicture} 
\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Shading a region between two polar curves

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