2

Consider the following (non-minimal) example of a rotation of a quadrilateral around a point:

\documentclass{article}

\usepackage{pstricks-add}
\usepackage{xfp}

\begin{document}

\def\Ax{-1}
\def\Ay{4}
\def\Bx{-2}
\def\By{3}
\def\Cx{-1}
\def\Cy{1}
\def\Dx{0}
\def\Dy{3}
\def\Ex{1}
\def\Ey{2}
\def\rotation{90}
\def\punkt(#1){%
  \def\str{0.1}
  \rput(#1){%
    \psline(-\str,-\str)(\str,\str)
    \psline(-\str,\str)(\str,-\str)}
  \uput[45](#1){$#1$}}%
\begin{pspicture}(-2.45,-1.12)(2.05,4.4)
  \pnodes(\Ax,\Ay){A}(\Bx,\By){B}(\Cx,\Cy){C}(\Dx,\Dy){D}(\Ex,\Ey){E}
 {\psset{
    linewidth = 1.5\pslinewidth,
    fillstyle = solid,
    fillcolor = cyan!50
  }
  \pspolygon(A)(B)(C)(D)
  \psrotate(E){\rotation}{%
    \pspolygon[
      linecolor = red
    ](\Ax,\Ay)(\Bx,\By)(\Cx,\Cy)(\Dx,\Dy)
  \uput[180]{\fpeval{360-\rotation}}(\Ax,\Ay){$A'$}
  \uput[270]{\fpeval{360-\rotation}}(\Bx,\By){$B'$}
  \uput[90]{\fpeval{360-\rotation}}(\Cx,\Cy){$C'$}
  \uput[90]{\fpeval{360-\rotation}}(\Dx,\Dy){$D'$}}}
  \uput[90](A){$A$}
  \uput[180](B){$B$}
  \uput[270](C){$C$}
  \uput[0](D){$D$}
  \punkt(E)
\end{pspicture}

\end{document}

output

The nodes A'--D' are not placed as I expected; I would like A' to be placed to the left of the vertex A, B' below the vertex B, and so on.

How do I achieve this?

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2 Answers 2

Reset to default
3

The trick (!!) is to not forget the polar axis, used for the direction along which the label is put, was also rotated. Whence:

\documentclass{article}

\usepackage{pstricks-add}
\usepackage{auto-pst-pdf}

\begin{document}

\def\Ax{-1}
\def\Ay{4}
\def\Bx{-2}
\def\By{3}
\def\Cx{-1}
\def\Cy{1}
\def\Dx{0}
\def\Dy{3}
\def\Ex{1}
\def\Ey{2}
\def\rotation{90}
\def\punkt(#1){%
  \def\str{0.1}
  \rput(#1){%
    \psline(-\str,-\str)(\str,\str)
    \psline(-\str,\str)(\str,-\str)}
  \uput[45](#1){$#1$}}%
\begin{pspicture}(-2.45,-1.12)(2.05,4.4)
  \pnodes(\Ax,\Ay){A}(\Bx,\By){B}(\Cx,\Cy){C}(\Dx,\Dy){D}(\Ex,\Ey){E}
 {\psset{
    linewidth = 1.5\pslinewidth,
    fillstyle = solid,
    fillcolor = cyan!50
  }
  \pspolygon(A)(B)(C)(D)
  \psrotate(E){\rotation}{%
    \pspolygon[
      linecolor = red
    ](\Ax,\Ay)(\Bx,\By)(\Cx,\Cy)(\Dx,\Dy)
  \uput[90]{-\rotation}(\Ax,\Ay){$A'$}
  \uput[180]{-\rotation}(\Bx,\By){$B'$}
  \uput[-90]{-\rotation}(\Cx,\Cy){$C'$}
  \uput[0]{-\rotation}(\Dx,\Dy){$D'$}}}
  \uput[90](A){$A$}
  \uput[180](B){$B$}
  \uput[270](C){$C$}
  \uput[0](D){$D$}
  \punkt(E)
\end{pspicture}

\end{document}

enter image description here

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2
  • You're welcome. It's a pleasure to help.
    – Bernard
    Commented Jun 6, 2016 at 19:34
  • @SvendTveskæg: I don't even remember what the removed code was supposed to do. If it works without it, I agree, of course. Thanks for having simplified!
    – Bernard
    Commented Apr 22, 2017 at 13:47
2 
\uput[180]{E}(\Ax,\Ay){$A'$}
\uput[270]{E}(\Bx,\By){$B'$}
\uput[0]{E}(\Cx,\Cy){$C'$}
\uput[90]{E}(\Dx,\Dy){$D'$}}}
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1
  • This only works for a rotation of 90 degrees, I think.
    – Svend Tveskæg
    Commented Jun 15, 2016 at 23:32

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