Graphics, Figures & Tables ⇒ Clip Region between a Secant and a Circle

[coachbennett1981]

Hello all,

I am trying to shade the section to the right of line segment L-M. I can't figure it out with \psclip feature. If anyone can help, that would be appreciated.

Code: Select all

\documentclass[12pt]{exam}
\usepackage{amsmath,amsfonts,amssymb} 
\usepackage{pstricks}
\usepackage{pstricks-add}

\begin{document}
  \begin{pspicture}(-3,02)(2,3)
    \pscircle(0,0){2}
    \uput[l](0,0){$N$}
    \psdot[dotsize=4pt](0,0)
    \psline(0,0)(2;45)
    \psline(0,0)(2;-45)
    \psline(2;45)(2;-45)
    \uput[ur](2;45){$L$}
    \uput[r](2;-45){$M$}
    \uput[r](2,0){$120^\circ$}
  \end{pspicture}
\end{document}

[coachbennett1981]

I used this code.

Code: Select all

\begin{psclip}{\pscircle(0,0){2}}
  \pswedge*[linecolor=lightgray](1.41,0){2}{-90}{90}
\end{psclip}

Is there an easier way? I had to use the unit circle and think a bit. But I got it.

[localghost]

Due to the date of this thread the solution is probably just for the record. But perhaps others who come here by search engine will find it useful.

Perhaps it is more convenient here to use a custom graphics object by \pscustom with a corresponding line style and fill color. This way you can specify the concerned area easier and more precise. The output is attached.

Code: Select all

% !TeX program = pdflatex
\documentclass[11pt]{standalone}
\usepackage[T1]{fontenc}
\usepackage{pstricks-add}
\usepackage{auto-pst-pdf}   % allow PSTricks code with PDFLaTeX
\usepackage{textcomp}

\begin{document}
  \begin{pspicture}[showgrid=false](-2,-2)(3,2)
    \pscustom[linestyle=none,fillcolor=lightgray,fillstyle=solid]{
      \psline(2;60)(2;-60)
      \psarc(0,0){2}{-60}{60}
    }
    \pscircle(0,0){2}
    \uput[l](0,0){$N$}
    \psdot[dotsize=4pt](0,0)
    \psline(0,0)(2;60)
    \psline(0,0)(2;-60)
    \psline(2;60)(2;-60)
    \uput[ur](2;60){$L$}
    \uput[dr](2;-60){$M$}
    \uput[r](2,0){120\textdegree}
  \end{pspicture}
\end{document}

Details about \pscustom can be found in the PSTricks base manual.


Thorsten