Re: Plotting problem

[Etienne Grossmann]

  Hi Matthias,

shing like

  xx = linspace (-7,7,100); 
  y1 = sin (xx); y2 = 0.8*sin(xx+pi/6); y3 = 0.64*sin(xx+pi/3);
  __gnuplot_raw__ ("set style data filledcurves y1=0;\n")
  plot (xx,y1,xx,y2,xx,y3)

?

  Hth,

  Etienne

On Tue, May 02, 2006 at 03:25:33PM +0200, Matthias Brennwald wrote:
# Dear all,
# 
# before reading further, a short warning: I'm a newbie (both with  
# Octave and with this list), so...
# 
# I am trying to write some code that plots a "waterfall diagram" (aka.  
# "cumulative spectral decay diagram", CSD diagram). An example of such  
# plot is available here: http://www.euronet.nl/users/temagm/audio/ 
# waterfall_focal.htm
# 
# I want this code to work both under Matlab and Octave. I use Octave  
# 2.1.72 on the Mac, but the code should not be limited to this  
# specific setup.
# 
# My approach to plotting the waterfall is this (see also example code  
# below): first, plot the curve in the back as a filled polygon. Then,  
# plot the next curve also as filled polygon above the one in the back;  
# and continue in the same way until the frontmost curve. With Matlab,  
# I can use 'fill3' easily plot these polygons. With plain vanilla  
# Octave, the only options I have is 'mesh' or '__gnuplot_splot__',  
# which I cannot make plot FILLED polygons. (I also tried the 'fill3'  
# command from Octave-forge, but with no luck. Also, I want my code to  
# be independent of Octave-forge, because Octave-forge is not available  
# as a 'stable' version from Fink for easy installation on the Mac.)
# 
# Any help or ideas?
# 
# Matthias
# 
# 
# 
# 
# An example illustrating my approach (and problem) is this:
# 
# **********************
# % First, make up three curves z(x) to play with. Each of the curves  
# have constant y (y=1,2,3):
# x = [0:100];
# y = [ 0:2 ];
# z = [   2+sin(x/10);
#          1.8 + 0.8*sin(x/11);
#          1.5 + 0.6*sin(x/12); ];
# 
# % append some points so we get closed curves:
# x = [ x x(end) x(1) x(1) ];
# z = [ z [0 0 0]' [0 0 0]' z(:,1) ];
# 
# for n=1:3
#      if exist('OCTAVE_VERSION') % we're running Octave
#          mesh(x,y(n),z(n,:)); % this plot TRANSPARENT polygons
#      else % we're running Matlab
#          poly=fill3(x,repmat(y(n),1,length(z(n,:))),z(n,:),'w'); %  
# this plots a filled polygon with fill color 'white'
#          set(poly,'EdgeColor','r'); % this sets the edge of the  
# polygon to 'red'
#      end
#      hold on
# end
# 
# hold off
# **********************
# 
# 
# 
# 
# -------
# Matthias Brennwald
# Lägernstrasse 6
# CH 8037 Zürich
# +41 (0)44 364 17 03
# address@hidden
# 
# 
# 
# _______________________________________________
# Help-octave mailing list
# address@hidden
# https://www.cae.wisc.edu/mailman/listinfo/help-octave

-- 
Etienne Grossmann ------ http://www.cs.uky.edu/~etienne