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>>>>> "Darren" == Darren Dale <dd...@co...> writes:

    Darren> Hi All, My research group submitted a paper for
    Darren> publication in a journal, and one of the requested changes
    Darren> was having the tick-marks formatted like $1x10^{-4}$ (for
    Darren> the latex-ers out there) rather than 1e-4, which was
    Darren> considered an unnecessary use of mathematical jargon. I
    Darren> wasn't the lead author on this particular paper, and
    Darren> therefore the plots were not created using Python and
    Darren> MPL. But I think this is a pretty standard formatting
    Darren> requirement in the scientific community. Would the
    Darren> creators of Matplotlib consider an option to format the
    Darren> ticks like this (does this capability exist and I havent
    Darren> found it yet)?

Yes, this would be nice.  Of course, you can manually format the ticks
using mathtext, eg, 

    from matplotlib.matlab import *

    rc('tick', labelsize=15)

    a=[8E8,10E8, 15E8]
    plot(a,a)

    ticks = arange(8,16)
    labels = ['$%d^{8}$'%val for val in ticks]
    set(gca(), xticks=ticks*1e8, yticks=ticks*1e8,
               xticklabels=labels, yticklabels=labels)

    show()

but it would be nice to provide some automatic facilities for this.

    Darren> In Matlab, when the tick labels require scientific
    Darren> notation, only the decimal component is listed in each
    Darren> tick label, and the exponential part is printed at the end
    Darren> of the axis. In Igor, the exponential part can be included
    Darren> in the y-axis label. Finally, one problem with formatting
    Darren> tick labels is how to deal with data spanning small
    Darren> ranges, but with large offsets, like
    Darren> array(range(10))+1e10. Maybe there is an interest in
    Darren> removing the offset from each tick label, and including it
    Darren> elsewhere in the figure? Then again, maybe that's getting
    Darren> too complicated.

This would definitely be a nice feature.  It would require a little
architectural change in the formatter.  Basically the formatter would
need to provide an additional method, eg get_offset, which would
return None (the current default) or a string like '$10^{-23}$.  The
axis, which calls the formatter, could check this value, and if not
None, render it to the proper place (eg left of x axis).  I could help
you with this part.  Below I'll include a script example showing how
to plot a tick offset which you can currently use for figures.
Basically, we'd just want to automate something along these lines.

    Darren> Is this attractive to the Matplotlib Gurus and Users? If
    Darren> so, is it something I could work on, or would it be best
    Darren> left to the masters?

There's only one path to becoming a master, of course, which is to
dive in.  It would be great if you work on this.  Getting ticking
right is pretty hard since there are so many pathological cases out
there.  But it looks like you work with that kind of data so you'll be
in a good position to find and fix the problem spots.  I think you
should take two approaches: 1) clean up the existing Locators and
Formatters when you find bugs and 2) define some new ones.  It
shouldn't be too hard to define a new formatter that does the mathtext
formatting for exponential ticking you've alluded to above.

The only (minor) downside to doing mathtext formatting is that the
font is likely different than non-mathtext on your figure.  There are
two ways to solve this: use the cmr font as the default for the entire
figure or better, support mathtext layout (super/subscripting) for any
font.  Right now we use the computer modern fonts for mathtext because
they have all the symbols, but there is no reason (other than time)
that we can't use the mathtext layout algorithms for
super/subscripting of non symbol fonts.  


Let me know how I can help...

JDH

# use an exponential tick offset
from matplotlib.matlab import *

rc('tick', labelsize=12)

a=[8E8,10E8, 15E8]
plot(a,a)

ticks = arange(8,16)
labels = ['%d'%val for val in ticks]

# place the offset in axes coords
t = text(-.075, -.075, r'$10^{8}\times$',
         transform=gca().transAxes,
         fontsize=14)
t.set_clip_on(False)

set(gca(), xticks=ticks*1e8, yticks=ticks*1e8,
    xticklabels=labels, yticklabels=labels)


show()

Hi All,

My research group submitted a paper for publication in a journal, and 
one of the requested changes was having the tick-marks formatted like 
$1x10^{-4}$ (for the latex-ers out there) rather than 1e-4, which was 
considered an unnecessary use of mathematical jargon. I wasn't the lead 
author on this particular paper, and therefore the plots were not 
created using Python and MPL. But I think this is a pretty standard 
formatting requirement in the scientific community. Would the creators 
of Matplotlib consider an option to format the ticks like this (does 
this capability exist and I havent found it yet)?

In Matlab, when the tick labels require scientific notation, only the 
decimal component is listed in each tick label, and the exponential part 
is printed at the end of the axis. In Igor, the exponential part can be 
included in the y-axis label. Finally, one problem with formatting tick 
labels is how to deal with data spanning small ranges, but with large 
offsets, like array(range(10))+1e10. Maybe there is an interest in 
removing the offset from each tick label, and including it elsewhere in 
the figure? Then again, maybe that's getting too complicated.

Is this attractive to the Matplotlib Gurus and Users? If so, is it 
something I could work on, or would it be best left to the masters?

Darren

> -----Original Message-----
> From: John Hunter [mailto:jdh...@ni...]
> Sent: Thursday, August 12, 2004 AM 8:49
> To: Shin
> Cc: matplotlib-users
> Subject: Re: [Matplotlib-users] better axis command?
>
>
>
> This is certainly easy enough  - does matlab also support
>
>     >> axis([-inf, 5, 0, 10]).
>
> in which case on the lower xlim is set automatically and the upper
> xlim is 5?

Yes. In my opinion, Using None is better than inf
because inf should be imported seperately in numarray
(from numarray.ieeespecial import nan, inf).

> I didn't know matlab had them :-( I'll add them.  In the meantime:
>

The xlim and ylim are ones I frequently use to adjust axis ranges.
I am quite sure many users will like the addition.
Note that xlim and ylim change only one axis without touching other axes,
such as automatic scaling.
Glad to contribute something to Matplotlib. Thanks for your effort.

Daehyok Shin

>>>>> "Shin" == Shin  <sd...@em...> writes:

    Shin> As you know, in MATLAB, axis([-inf inf 0 10]) means that the
    Shin> range of x-axis is determined automatically while the range
    Shin> of y-axis is set manually to the range from 0 to 10.

    Shin> In current Matplotlib, it seems there is no support for that
    Shin> kind of partial range setting.  If so, how about adding a
    Shin> little intelligence on the axis function, like

    >>>> axis([None, None, 0, 10]).

This is certainly easy enough  - does matlab also support

    >> axis([-inf, 5, 0, 10]).

in which case on the lower xlim is set automatically and the upper
xlim is 5?

    Shin> And, any specific reason there is no xlim or ylim function?

I didn't know matlab had them :-( I'll add them.  In the meantime:

  ax.set_xlim((xmin, xmax))

or 
  
  set(gca(), 'xlim', (xmin, xmax))

or 

  set(ax, xlim=(xmin, xmax))

and so on ...


    Shin> -- Daehyok Shin (Peter) Geography Department Univ. of North
    Shin> Carolina-Chapel Hill



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As you know, in MATLAB, axis([-inf inf 0 10]) means that
the range of x-axis is determined automatically while
the range of y-axis is set manually to the range from 0 to 10.

In current Matplotlib, it seems there is no support for that kind of
partial range setting.
If so, how about adding a little intelligence on the axis function, like

>>> axis([None, None, 0, 10]).

And, any specific reason there is no xlim or ylim function?

-- 
Daehyok Shin (Peter)
Geography Department
Univ. of North Carolina-Chapel Hill