1## Copyright (C) 1998-2003 Joao Cardoso. 2## 3## This program is free software; you can redistribute it and/or modify it 4## under the terms of the GNU General Public License as published by the 5## Free Software Foundation; either version 2 of the License, or (at your 6## option) any later version. 7## 8## This program is distributed in the hope that it will be useful, but 9## WITHOUT ANY WARRANTY; without even the implied warranty of 10## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11## General Public License for more details. 12## 13## This file is part of plplot_octave. 14 15function p9 16 17 global pl_automatic_replot 18 t = pl_automatic_replot; 19 pl_automatic_replot = 0; 20 21 as = autostyle; 22 autostyle ("off"); 23 24 ls = legend; 25 legend "off" 26 27 step = 0.2; 28 x = -2:step:2; 29 y = -2:step:2; 30 [xx,yy] = meshgrid(x,y); 31 z = xx .* exp(-xx.^2 - yy.^2); 32 [gy, gx] = gradn(z,step,step); 33 title("Vector field example"); 34 contour(x,y,z) 35 hold on; 36 arrows(yy,xx,gx./2,gy./2); 37 hold off 38 plflush; 39 40 legend(ls); 41 autostyle(as); 42 pl_automatic_replot = t; 43 44endfunction 45