Re: [Matplotlib-users] Update a contour plot

[Ralph K. <ral...@go...>]

Hey everybody,
thank you for your answers. I use matplotlib from qt4 now. What I do is
creating a widget in a gui and using this for plotting. The plot is to
refreshed by clicking on a button. This works perfectly fine,
until I start adding a colorbar to the plot.
When I add the colorbar and replot the whole thing, the plot doesnt
fill up the area of the widget in the gui, but roughly 80% of the
horizontal extent of the last plot. So when I replot in the axes, my
plot shrinks around 20% horizontally every time I click on the button.
I found out how to delete the old colorbar, but where do I tell
matplotlib to plot into the whole extent of the plot?


This is the widget i instantiate in my gui:


class MyMplCanvas(FigureCanvas):
	def __init__(self, parent=None, width = 10, height = 12, dpi = 100, 
sharex = None, sharey = None):
	 self.fig = Figure(figsize = (width, height), dpi=dpi, facecolor = 
'#FFFFFF')
	self.ax = self.fig.add_subplot(111, sharex = sharex, sharey = sharey)
	self.fig.subplots_adjust(left=0.1, bottom=0.15, right=0.9, top=0.9)
	self.xtitle="x [a.u.]"
	self.ytitle="y [a.u.]"
	self.PlotTitle = ""
	self.grid_status = True
	self.xaxis_style = 'linear'
	self.yaxis_style = 'linear'
	self.format_labels()
	self.ax.hold(False)
.......


And this would be the code I call for plotting:

	elif self.ui.radioButton_theta.isChecked() :
		data = N.vstack([ self.data_theta[self.nx/2:,:,self.filepos], 
self.data_theta[:self.nx/2,:,self.filepos]] )
		title_str =  'Theta T.%03d' % self.filepos

		self.ui.widget.canvas.ax.collections = []
		plt = self.ui.widget.canvas.ax.contourf(data)
		self.ui.widget.canvas.fig.colorbar(plt)
		self.ui.widget.canvas.PlotTitle = title_str
		self.ui.widget.canvas.print_figure('plot')

I thought the call self.ui.widget.canvas.ax.collections = [] clears the 
axes. Any ideas?

Cheers, Ralph


Eric Firing wrote:
> Matthias Michler wrote:
>> Hi Ralph,
>>
>> I don't think there exists a function like the line-'set_data'-method for 
>> collections, which are generated by 'contour'. This particular method of 
>> lines only changes the data but leave anything else unchanged.
>> I attached an easy approach of updating a contour plot (simply deleting old 
>> collections), but I'm not sure that this is the best solution.
> 
> I don't think you area gaining anything at all by manually deleting the 
> collections.  Better to just clear the axes, or clear the figure, and 
> make a fresh plot.
> 
> Eric
> 
> 
>> Kind regards,
>> Matthias
>>
>> On Monday 28 September 2009 13:52:42 Ralph Kube wrote:
>>> Hi,
>>> is there a way to update a contour plot? I need to display a series of
>>> contour plots from a directory with data files and want to view them
>>> consecutively, preferrably without building a gui for it. Is there an
>>> easy way out?
>>>
>>> Cheers, Ralph