matplotlib-users Mailing List for matplotlib

> I only started using matplolib a few days ago, but I think I know how 
> to do what you want:
...
Thanks. Once I figured out how to get the axes to operate on (gca()
:confused:) I was able to easily adapt your solution to my needs.
Skip

On Sat, Oct 24, 2009 at 1:02 PM, Dr. Phillip M. Feldman <
pfe...@ve...> wrote:
>
> I'd like to create a plot showing motor current, efficiency, speed, and
> output power versus input power, with all four curves on a single plot and
> four y axes. I've looked at the example in
> http://matplotlib.sourceforge.net/examples/api/two_scales.html, and also
> at
> the doc string for twinx. It looks as though twinx will let me create two y
> axes, but in this case I need four. Can this be done with matplotlib?
> --
> View this message in context:
> http://www.nabble.com/Possible-to-get-four-y-axes-on-a-single-plot--tp26041500p26041500.html
> Sent from the matplotlib - users mailing list archive at Nabble.com.
>
>
>
Using axes_grid you can get multiple y-axes. See for example:
http://matplotlib.sourceforge.net/examples/axes_grid/demo_parasite_axes2.html
>
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-- 
Gökhan

I'd like to create a plot showing motor current, efficiency, speed, and
output power versus input power, with all four curves on a single plot and
four y axes. I've looked at the example in
http://matplotlib.sourceforge.net/examples/api/two_scales.html, and also at
the doc string for twinx. It looks as though twinx will let me create two y
axes, but in this case I need four. Can this be done with matplotlib?
-- 
View this message in context: http://www.nabble.com/Possible-to-get-four-y-axes-on-a-single-plot--tp26041500p26041500.html
Sent from the matplotlib - users mailing list archive at Nabble.com.

Hi,
> * The time ranges are large (one-second samples over a period of
> several days) and I find the x axis label formats are often
> inappropriate to the scale. How to I control the format of
> the x axis labels?
>
I only started using matplolib a few days ago, but I think I know how 
to do what you want:
----------------------------------------
import matplotlib.dates as mdates # To read timestamps
 ...
xAxisTimeFormat = '%a\n%H:%M' # Format of time stamps on x-axis
hourLocator = mdates.HourLocator(interval=5) # Every 5 hours
minuteLocator = mdates.MinuteLocator(interval=30) # Every half hour
 ...
ax.xaxis.set_major_locator(hourLocator) # Set major tick marks
ax.xaxis.set_minor_locator(minuteLocator) # Set minor tick marks
ax.xaxis.set_major_formatter(mdates.DateFormatter(xAxisTimeFormat)) # 
Format x-axis labels
----------------------------------------
I have a full example of plots that have a point every minute over the 
course of days:
 http://www.hep.wisc.edu/cms/comp/routerqMonitor/index.html
with a link to the full python script at the bottom.
Mike

I'm using matplotlib.pyplot.plot to plot values from CSV files where
the x axis data are datetime objects. This works well except for two
issues:
 * The time ranges are large (one-second samples over a period of
 several days) and I find the x axis label formats are often
 inappropriate to the scale. How to I control the format of
 the x axis labels?
 * Samples are only collected for part of the time each day, say
 from 01:00 to 15:00. How can I elide the gaps and perhaps
 plot a vertical line to signify the elided gaps?
Thanks,
Skip Montanaro

Werner F. Bruhin wrote:
> Installed Py 2.6.3 and I don't see the issue there, but not all 
> libraries I use are on 2.6 yet.
>
> So, I thought lets install Python(x, y) and give this a try, but I can't 
> find a Python 2.5.x version of it - is this still available?
>
> Werner
>
> P.S.
> Will totally de-install 2.5 again and try once more.
> 
I got it working by adding "C:\Python25" to the path environment 
variable. Works but smells very much like a work around.
Werner

# For detailed comments on animation and the techniqes used here, see
# the wiki entry http://www.scipy.org/Cookbook/Matplotlib/Animations
import os
import sys
#import matplotlib
#matplotlib.use('Qt4Agg')
from matplotlib.figure import Figure
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
import matplotlib.transforms as mtransforms
import matplotlib.cm as cm
from PyQt4 import QtCore, QtGui
ITERS = 100
import numpy as np
import time
class BlitQT(FigureCanvas):
 def __init__(self):
 FigureCanvas.__init__(self, Figure())
 fig = self.figure
 self.ax = fig.add_axes([0.1,0.7,0.8,0.2])
 self.ax.grid()
 self.draw()
 NUMBER_OF_DATA = 1024
 self.x = np.arange(NUMBER_OF_DATA)
 
 self.ax2 = fig.add_axes([0.1,0.4,0.8,0.2])
 self.ax2.grid()
 self.draw()
 self.old_size = self.ax.bbox.width, self.ax.bbox.height
 
 self.cnt = 0
 # create the initial lines
 self.line, = self.ax.plot(self.x, self.x, 'r', animated=True, lw=.5)
 self.line2, = self.ax2.plot(self.x, self.getY(), animated=True, lw=.5)
 self.bbox = mtransforms.Bbox.from_bounds(32,24,608-32,407)
 self.bbox = mtransforms.Bbox.from_bounds(64,192,576-64,432-193)
 
 print self.ax.bbox.corners()
 print self.ax2.bbox.corners()
 self.background = self.copy_from_bbox(self.ax.bbox)
 self.background2 = self.copy_from_bbox(self.ax2.bbox)
 self.tstart = time.time()
 self.startTimer(0)
 def getY(self):
 return np.random.random_sample(1024)
 
 def timerEvent(self, evt):
 #if (self.cnt % 3) == 0:
 current_size = self.ax.bbox.width, self.ax.bbox.height
 if self.old_size != current_size:
 self.old_size = current_size
 self.ax.clear()
 self.ax.grid()
 self.ax2.clear()
 self.ax2.grid()
 self.draw()
 self.background = self.copy_from_bbox(self.ax.bbox)
 self.background2 = self.copy_from_bbox(self.ax2.bbox)
 # update the data
 self.line.set_ydata(self.x+(self.cnt%100))
 self.line2.set_ydata(self.getY())
 # restore the clean slate background
 self.restore_region(self.background)
 self.restore_region(self.background2)
 
 # just draw the animated artist
 self.ax.draw_artist(self.line)
 self.ax2.draw_artist(self.line2)
 # and blit the different zones
 self.blit(self.ax.bbox)
 self.repaint()
 self.blit(self.ax2.bbox)
 self.repaint()
 
 
 if self.cnt == 0:
 self.draw()
 if not (self.cnt%ITERS):
 # print the timing info and quit
 print 'FPS:' , ITERS/(time.time()-self.tstart)
 self.tstart = time.time()
 self.cnt += 1
app = QtGui.QApplication(sys.argv)
widget = BlitQT()
widget.show()
app.exec_()

Deinstalled 2.5.4 and installed again, same issue. Deinstalled again 
and installed 2.5.2, both times I also deleted python25 folder.
Running barchart_demo.py directly works (c:\python25\python.exe 
pathto\barchart_demo.py).
Running it from within idle I get the same exception again:
Traceback (most recent call last):
 File "D:\Dev\aaTests\matplotlib\barchart_demo.py", line 3, in <module>
 import matplotlib.pyplot as plt
 File "C:\Python25\Lib\site-packages\matplotlib\pyplot.py", line 6, in 
<module>
 from matplotlib.figure import Figure, figaspect
 File "C:\Python25\Lib\site-packages\matplotlib\figure.py", line 16, in 
<module>
 import artist
 File "C:\Python25\Lib\site-packages\matplotlib\artist.py", line 5, in 
<module>
 from transforms import Bbox, IdentityTransform, TransformedBbox, 
TransformedPath
 File "C:\Python25\Lib\site-packages\matplotlib\transforms.py", line 
34, in <module>
 from matplotlib._path import affine_transform
ImportError: DLL load failed: Le module spécifié est introuvable.
Noticed that msvcp71.dll is being installed by mpl (at least that is 
what I see in matplotlib-wininst.log).
"cd" to the folder of the script and running it again directly with 
Python I see the error again.
What could cause this? Maybe one of the msvcp71.dll is incompatible 
with stuff already loaded by Python?
Will keep experimenting and see if I can get Boa to work with mpl
Werner

# For detailed comments on animation and the techniqes used here, see
# the wiki entry http://www.scipy.org/Cookbook/Matplotlib/Animations
import os
import sys
#import matplotlib
#matplotlib.use('Qt4Agg')
from matplotlib.figure import Figure
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas
import matplotlib.transforms as mtransforms
import matplotlib.cm as cm
from PyQt4 import QtCore, QtGui
ITERS = 100
import numpy as np
import time
class BlitQT(FigureCanvas):
 def __init__(self):
 FigureCanvas.__init__(self, Figure())
 fig = self.figure
 self.ax = fig.add_axes([0.1,0.7,0.8,0.2])#(.05,.55,.9,.4))
 self.ax.grid()
 self.draw()
 NUMBER_OF_DATA = 1024
 self.x = np.arange(NUMBER_OF_DATA)
 
 self.ax2 = fig.add_axes([0.1,0.4,0.8,0.2])#(.05,.05,.9,.4))
 self.ax2.grid()
 self.draw()
 self.old_size = self.ax.bbox.width, self.ax.bbox.height
 
 self.cnt = 0
 #canvas = axe.figure.canvas
 # create the initial line
 #self.x = np.arange(0,2*np.pi,0.01)
 
 #line, = p.plot(x, npy.sin(x), animated=True, lw=2)
 self.line, = self.ax.plot(self.x, self.x, 'r', animated=True, lw=.5)
 self.line2, = self.ax2.plot(self.x, self.getY(), animated=True, lw=.5)
 #self.draw()
 self.bbox = mtransforms.Bbox.from_bounds(32,24,608-32,407)
 self.bbox = mtransforms.Bbox.from_bounds(64,192,576-64,432-193)
 
 print self.ax.bbox.corners()
 print self.ax2.bbox.corners()
 self.background = self.copy_from_bbox(self.ax.bbox)
 self.background2 = self.copy_from_bbox(self.ax2.bbox)
 self.tstart = time.time()
 self.startTimer(10)
 def getY(self):
 return np.random.random_sample(1024)
 
 def timerEvent(self, evt):
 if (self.cnt % 3) == 0:
 current_size = self.ax.bbox.width, self.ax.bbox.height
 if self.old_size != current_size:
 self.old_size = current_size
 self.ax.clear()
 self.ax.grid()
 self.ax2.clear()
 self.ax2.grid()
 self.draw()
 self.background = self.copy_from_bbox(self.ax.bbox)
 self.background2 = self.copy_from_bbox(self.ax2.bbox)
 # update the data
 self.line.set_ydata(self.x+(self.cnt%100))
 self.line2.set_ydata(self.getY())
 # restore the clean slate background
 self.restore_region(self.background)
 self.restore_region(self.background2)
 #self.draw()
 
 
 # just draw the animated artist
 self.ax.draw_artist(self.line)
 self.ax2.draw_artist(self.line2)
 if (self.cnt % 3) == 1:
 # just redraw the axes rectangle
 self.blit(self.ax.bbox)
 if (self.cnt % 3) == 2:
 self.blit(self.ax2.bbox)
 
 #self.blit(self.bbox)
 #self.blit(self.ax.get_figure().bbox) 
 
 
 if self.cnt == 0:
 # TODO: this shouldn't be necessary, but if it is excluded the
 # canvas outside the axes is not initially painted.
 self.draw()
 pass
 if not (self.cnt%ITERS):#==ITERS:
 # print the timing info and quit
 print 'FPS:' , ITERS/(time.time()-self.tstart)
 self.tstart = time.time()
 # sys.exit()
 #else:
 self.cnt += 1
app = QtGui.QApplication(sys.argv)
widget = BlitQT()
widget.show()
app.exec_()

Installed Py 2.6.3 and I don't see the issue there, but not all 
libraries I use are on 2.6 yet.
So, I thought lets install Python(x, y) and give this a try, but I can't 
find a Python 2.5.x version of it - is this still available?
Werner
P.S.
Will totally de-install 2.5 again and try once more.