Re: Hold on and hold off in octave-2.9.8

[Joe Koski]

on 9/9/06 2:30 PM, Joe Koski at address@hidden wrote:

> on 9/9/06 2:09 PM, John W. Eaton at address@hidden wrote:
> 
>> On  9-Sep-2006, Joe Koski wrote:
>> 
>> | Hi all,
>> | 
>> | I have a loop in one of my scripts:
>> | 
>> | for i = 1:num_c2f
>> |   ifig = ifig + 1;
>> |   figure(ifig);
>> |   clg;
>> |   legend('off');
>> |   axis('auto');
>> |   title(['Coarse to Fine ',int2str(i),' vs. Signal']);
>> |   xlabel ("Time, s")
>> |   ylabel ("Amplitude")
>> |   hold on;
>> |   plot(t,x,'r');
>> |   plot(t,c2f(i,:),'b');
>> |   hold off;
>> | end
>> | 
>> | With octave-2.1.73, the "hold on" and "hold off" serve to superimpose the
>> | two plot commands onto one plot frame. With octave-2.9.8, only the second
>> | plot appears in the axes, and the first plot disappears. This is all on my
>> | Mac with octave builds from scratch on OS X 10.4.7, Xcode-2.4, etc.
>> | 
>> | Has the use of "hold on" changed?
>> 
>> It should not have changed.
>> 
>> I can't run your code above since I don't have all the data required,
>> but the following works for me:
>> 
>>   x = linspace (-10, 10, 200)';
>>   hold on
>>   plot (x, sin (x));
>>   plot (x, cos (x));
>>   hold off
>> 
>> Does this work for you?
>> 
>> jwe
> 
> John,
> 
> Yes, the simple test works correctly on my machine, both when I paste
> line-by-line, and when I place the commands in a simple test_hold_on.m file.
> 
> I'll be in and out today, but I can try things like constructing a test loop
> and placing other items like legend() inside the loop. It takes my code
> about 5 minutes to get to that sequence of plots, so I need to come up with
> a faster case for debugging that still replicates the problem.
> 
> This is the second time that this has happened, but the loops are very
> similar.
> 
> When I combined the plot commands into a single plot command, I did get what
> I wanted.
> 
> Joe
> 
John,

After much tinkering, I couldn't exactly duplicate the problem in a short
script, although the problem in the long script is very reproducible and can
be controlled by using a single plot command (without hold on and hold off).

The problem seems to be associated somehow with figure.m or what is called
there. When I was using octave-2.9.7, figure.m wasn't finished, so I used my
old figure.m that allows me to set fontsize and fontname via global
variables and a __gnuplot_set__ command. It almost works. Now 2.9.8 has
figure.m updated, but, at least on my Mac, all figures appear with the plot
window labeled "Figure 0", not with the number assigned by n in figure(n).
When I attempted to fix that, I got into some logic problems in
__plot_globals__.m, so I punted (it's football season).

I guess I'll concede until I understand how to set the figure window number
correctly.

Is it an octave bug that every plot window is Figure 0, or is it just my Mac
version?

Joe