scilab/modules/graphics/macros/loglog.sci

   1 // Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
   2 // Copyright (C) 2020 - Stéphane MOTTELET
   3 //
   4 // This file is hereby licensed under the terms of the GNU GPL v2.0,
   5 // For more information, see the COPYING file which you should have received
   6 // along with this program.
   7
   8 function loglog(varargin)
   9     [lhs,rhs]=argn(0);
  10
  11     if ~rhs
  12        w=logspace(-2,2,1000);
  13        s=%i*w;
  14        g=[];
  15        leg=[];
  16        for alpha=logspace(-2,1,4);
  17          g=[g;(1)./(s.^2+alpha*s+1)];
  18        end
  19        clf("reset")
  20
  21        loglog(w,abs(g));
  22
  23        title("$\LARGE \left|s^2/(s^2+\alpha s+1)\right|\mbox{ for }s=i\omega$")
  24        xlabel("$\LARGE \omega$")
  25        return
  26     end
  27
  28     current_figure = gcf();
  29     cur_draw_mode = current_figure.immediate_drawing;
  30     current_figure.immediate_drawing = "off";
  31
  32     ok = isempty(gca().children) || and(gca().data_bounds([1 3]) > 0);
  33     set(gca(),"log_flags","nn")
  34     try
  35         plot(varargin(:))
  36         if ok
  37             set(gca(),"log_flags","ll")
  38         end
  39     catch
  40         current_figure.immediate_drawing = cur_draw_mode;
  41         error(lasterror(%t))
  42     end
  43
  44     current_figure.immediate_drawing = cur_draw_mode;
  45 endfunction