Re: [Matplotlib-users] Labels in a dynamic graph

[Matthias M. <Mat...@gm...>]

Hello Amit,

On Sunday 23 March 2008 09:54, Amit Finkler wrote:
> Hi everyone,
>
>
> I am using matplotlib to dynamically plot a graph with both my x and y
> points taken from a measurement device. That is to say, in each
> iteration of my while loop I'm reading two variables which I then want
> to plot with matplotlib.
>
>
> I wrote something which goes like this (disregard the Gnuplot - that's
> what I'm trying to replace with matplotlib...)
>
>
>
>     import gpib, Numeric, time, Gnuplot, mymodule, threading
>     from pylab import *
>
>
>
>     def cooldown(filename, dmm_gpib, lake_gpib):
>
>     """this program scans dummy and reads HP and Lakeshore"""
>
>     A             = Numeric.arange(-1, 1, .1)
>     delay         = 1
>     f = open(filename,'w')
>
>
>     X = []
>     Y = []
>     figure(2)
>     hold(False)
>         try:
>             while A[0]<10:
>
>                 gpib.write(lake_fd, 'SDAT?')
>                 gpib.write(hp_fd, 'read?')
>                 time.sleep(delay)
>                 val1 = float(gpib.read(lake_fd, 30))
>                 val2 = float(gpib.read(hp_fd, 30))
>                 X.append(val1)
>                 Y.append(val2)
>                 plot(X,Y,'.-')
>                 f.write(str(val1) + '\t' + str(val2) + '\n')
>                 f.flush()
>
> I'm running this code in ipython with the -pylab option, so I don't need
> to use show(). My question is, how do I maintain a *constant* xlabel and
> ylabel without having to redraw them each time I append a point to the
> graph? If I try xlabel('something') then obviously it's cleared each
> time I use plot(X,Y).

I'm not sure I understand well, but if one uses xlabel("something") before the 
while-loop or just after building the figure, it is not redrawn after 
plotting.

regards
Matthias