matplotlib-users Mailing List for matplotlib

Hi all,
I am using Matplotlib 1.0.1 and am seeing weird behaviour with mplot3d and 
ticker formatters, and I think I need to submit a patch to axes3d, but am not 
sure how much it will break, because format_zdata() and format_coord() look to 
be defined inconsistently.

When trying to rotate a plot, which was created including the following 
commands,
  ...
  ax.plot(x[0,alow:atop],x[1,alow:atop],x[2,alow:atop],c=rgb.tolist())
  ax.w_xaxis.set_major_locator(tic.LinearLocator(3))
  ax.w_xaxis.set_major_formatter(tic.FormatStrFormatter(''))
  ax.w_yaxis.set_major_locator(tic.LinearLocator(3))
  ax.w_yaxis.set_major_formatter(tic.FormatStrFormatter(''))
  ax.w_zaxis.set_major_locator(tic.LinearLocator(3))
  ax.w_zaxis.set_major_formatter(tic.FormatStrFormatter(''))
  plt.draw()
  ...

I received the following backtrace and error message:

/usr/lib64/python2.6/site-packages/matplotlib/backend_bases.pyc in 
mouse_move(self, event)
   2393         if event.inaxes and event.inaxes.get_navigate():
   2394 
-> 2395             try: s = event.inaxes.format_coord(event.xdata, 
event.ydata)
   2396             except ValueError: pass
   2397             except OverflowError: pass

/usr/lib64/python2.6/site-packages/mpl_toolkits/mplot3d/axes3d.pyc in 
format_coord(self, xd, yd)
    474 
    475         xs = self.format_xdata(x)
--> 476         ys = self.format_ydata(y)
    477         zs = self.format_ydata(z)
    478         return 'x=%s, y=%s, z=%s' % (xs, ys, zs)

/usr/lib64/python2.6/site-packages/mpl_toolkits/mplot3d/axes3d.pyc in 
format_ydata(self, y)
    424         except TypeError:
    425             fmt = self.w_yaxis.get_major_formatter()
--> 426             return sensible_format_data(fmt, y)
    427 
    428     def format_zdata(self, z):

/usr/lib64/python2.6/site-packages/mpl_toolkits/mplot3d/axes3d.pyc in 
sensible_format_data(self, value)
     26     if abs(value) > 1e4 or abs(value)<1e-3:
     27         s = '%1.4e' % value
---> 28         return self._formatSciNotation(s)
     29     else:
     30         return '%4.3f' % value

AttributeError: FormatStrFormatter instance has no attribute 
'_formatSciNotation'

---
I am using FormatStrFormatter('') to try to obtain an empty tick.

[1] It looks like sensible_format_data() assumes that self is class 
ScalarFormatter(Formatter), since this is the only ticker Formatter that has 
attribute _formatSciNotation(s). As far as I can tell, this means that 
sensible_format_data(fmt,y) should *only* be called if fmt has class 
ScalarFormatter(Formatter).


[2] In axes3d.py, I see:

    def format_zdata(self, z):
        """
        Return z string formatted.  This function will use the attribute
        self.fmt_zdata if it is callable, else will fall back on the yaxis
        major formatter
        """
        try:
            return self.fmt_zdata(z)
        except (AttributeError, TypeError):
            fmt = self.w_zaxis.get_major_formatter()
            return sensible_format_data(fmt, z)

To me, it looks like the call to sensible_format_data(fmt, z) is wrong. The 
same error occurs in format_xdata() and format_ydata(). So I would like to 
submit a patch for format_xdata(), format_ydata(), format_zdata(), e.g.:

    def format_zdata(self, z):
        """
        Return z string formatted.  This function will use the attribute
        self.fmt_zdata if it is callable, else will fall back on the zaxis
        major formatter
        """
        try:
            return self.fmt_zdata(z)
        except (AttributeError, TypeError):
            fmt = self.w_zaxis.get_major_formatter()
            try:
                return sensible_format_data(fmt, z)
            except (AttributeError, TypeError):
                return format_data(fmt, z)


[3] But I am also worried about the comment "else will fall back on the yaxis 
major formatter". Shouldn't this say "the zaxis major formatter", since that 
is what the code does? Or should the code use the yaxis major formatter, since 
that is what the documentation says? The documentation 
http://matplotlib.github.com/mpl_toolkits/mplot3d/api.html agrees with the 
comment and not with the code.


[4] In def format_coord(self, xd, yd), I see

        xs = self.format_xdata(x)
        ys = self.format_ydata(y)
        zs = self.format_ydata(z)

Why doesn't the last line say 
        zs = self.format_zdata(z)
?

Best, Paul

Hello all,

I am trying to change the position of the xlabel/ylabel with respect to the
xaxis/yaxis. Particularly, I was trying to get the "xlabel" closer to the
"xaxis" and the "ylabel" closer to the "yaxis", for which I was using the
lines indicated with '#<-------' in the following sample code:
#----
from pylab import *
from numpy import *
x = linspace(0,1,10)
y = x**2
plot(x, y)
xlabel('xname', position=(0.5,0.1)) #<------
ylabel('yname', position=(0.1,0.5)) #<------
#----
My understanding was that "position=(xpos,ypos)" would place the label
anywhere I wanted, though there is problem. Let me take "xlabel" as an
example. I can successfully move the "xlabel" parallel to the "xaxis" by
setting the quantity "xpos" anywhere from 0 to 1 (0.5 being the center of
the "xaxis"). However, for moving the "xlabel" closer to or further from the
"xaxis" I change the value of "ypos" but it does NOT do anything, i.e. the
"xlabel" stays at the same distance from the "xaxis". The equivalent problem
occurs with the "ylabel", i.e. I can move "ylabel" parallel to the "yaxis"
but I cannot get it any closer.
I am aware that I can "create a label" and place it anywhere by using  the
text() command. Yet, it would be better if I can get the label placement
done with the xlabel/ylabel command so that I can eventually control the
label placement via rcParams.update().

Many thanks in advance.

carlo
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On Sun, Mar 20, 2011 at 2:08 PM, Xavier Gnata <xav...@gm...> wrote:
> Hi,
>
> It looks like the
> http://matplotlib.svn.sourceforge.net/viewvc/matplotlib/branches/py3k/
> in dead.
> The last commit was 8months ago.
>
> Numpy is ok with python3.1, scipy is ok, nose is ok, ipython is usable.
> Ubuntu already provides python-tk for python3.x
> It would be nice to port matplotlib to python3.
> Is there a plan? another svn/git branch?

https://github.com/matplotlib/matplotlib-py3

Hi,

It looks like the 
http://matplotlib.svn.sourceforge.net/viewvc/matplotlib/branches/py3k/ 
in dead.
The last commit was 8months ago.

Numpy is ok with python3.1, scipy is ok, nose is ok, ipython is usable.
Ubuntu already provides python-tk for python3.x
It would be nice to port matplotlib to python3.
Is there a plan? another svn/git branch?

Xavier

--- On Wed, 3/16/11, Daniel Welling <dan...@gm...> wrote:
After
 playing with backends quite a bit, I have found that the best one in 
terms of speed, robustness, and features is Qt4Agg - especially on OSX, 
where the MacOSX backend is buggy and many others just don't plain 
work.  



Why do you think that the MacOSX backend is buggy?

--Michiel.