如何在以下示例中剪辑 \psplotImp 命令？

Question

这是我的代码。

\documentclass[pstricks,border=10pt]{standalone}
\usepackage{pstricks-add,pst-plot,pst-func}
\begin{document}
    \def\funcone{6-x}
    \def\functwo{7-x}
    \begin{pspicture}(-1,-1)(8,8)
    \psplot[linestyle=dashed,linecolor=red,algebraic]{0}{6}{\funcone}
    \psplot[linestyle=dashed,linecolor=red,algebraic]{0}{7}{\functwo}
%   \psplotImp[linecolor=red,stepFactor=0.1](0,-1)(6,5){x^2+x*y+y^2-8*x-7*y+15}
    \psaxes[showorigin=false]{->}(0,0)(-.5,-.5)(8,8)[$x$,-90][$y$,0]%[labels=none,ticks=none]
    \psclip[linestyle=none]{%
        \psplotImp[stepFactor=0.1,algebraic](-1,-1)(7,7){ x^2+x*y+y^2-8*x-7*y+15 }}
        \pscustom[fillstyle=solid,fillcolor=green!80!orange,algebraic]{%
            \psplot{0}{6}{\funcone}
            \psplot{7}{0}{\functwo}
            \closepath}
    \endpsclip  
    \end{pspicture}
\end{document}

输出图片

它应该是

注意：如果您想引入一些新的东西，您可以重现我的代码！

另一种使用方式pst-contourplot！

\documentclass[pstricks,border=10pt]{standalone}
\usepackage{pst-contourplot,pstricks-add}
\begin{document}
    \def\funcone{6-x}
    \def\functwo{7-x}
    \begin{pspicture}(-1,-1)(8,8)
    \psaxes[showorigin=false]{->}(0,0)(-.5,-.5)(8,8)[$x$,-90][$y$,0]
    \psclip[linestyle=none,algebraic]{%
        \pscustom{\psplot{0}{6}{\funcone}   \psplot{7}{0}{\functwo}     \closepath} }
    \psContourPlot[algebraic,
                   a=0.05,
                   linecolor=red,
                   Fill,fillcolor=green!50!orange,
                   function=x^2+x*y+y^2-8*x-7*y+15](-1,-1)(7,7)
    \endpsclip
    \psplot[linestyle=dashed,linecolor=red,algebraic]{0}{6}{\funcone}
    \psplot[linestyle=dashed,linecolor=red,algebraic]{0}{7}{\functwo}
    \psContourPlot[algebraic,a=0.05,linecolor=red,function=x^2+x*y+y^2-8*x-7*y+15](-1,-1)(7,7)
    \end{pspicture}
\end{document}

Answer 1

您不能使用 \pstPlotImp，该线不是函数。那只是单个点。但是，\psellipse[rot=-45](3,2)(2.85,1.65)是相同的曲线。

\documentclass[pstricks,border=10pt]{standalone}
\usepackage{pstricks-add}
\begin{document}
\begin{pspicture}(-1,-1)(8,8)
  \psaxes[showorigin=false]{->}(0,0)(-.5,-.5)(8,8)[$x$,-90][$y$,0]
  \psclip{\psellipse[rot=-45,linestyle=none](3,2)(2.85,1.65)}
    \pspolygon[linestyle=none,fillstyle=solid,fillcolor=red!50](6,0)(7,0)(0,7)(0,6)
  \endpsclip  
  \psellipse[rot=-45,linestyle=dashed](3,2)(2.85,1.65)
  \psset{linecolor=red,linestyle=dashed}
  \psline(7,0)(0,7)
  \psline(6,0)(0,6)
\end{pspicture}
\end{document}