Re: [Matplotlib-users] How to improve colorbar scaling?

Using the set_powerlimits method didn't help?

As far as I know, the current implementation does not allow a custom
scale factor.
But if the scale factor is power of 10 (10, 100, 1000, ...), I believe
using set_powerlimits method (as in my previous example, or some
variation) is good enough.

Let me know if it does not work or you have any other problem.
Regards,

-JJ


On Tue, Aug 17, 2010 at 3:17 AM, Jeremy Conlin <jlc...@gm...> wrote:
> On Sun, Aug 15, 2010 at 10:49 PM, Jae-Joon Lee <lee...@gm...> wrote:
>> On Fri, Aug 13, 2010 at 3:34 AM, Jeremy Conlin <jlc...@gm...> wrote:
>>> I have a problem with the scaling of the numbers on a colorbar.  The
>>> problem occurs when the numbers used as colorbar labels need to be
>>> scaled (i.e. by 1E3).  The colorbar correctly puts the scaling value
>>> on the top of the colorbar, but instead of of multiplying by a scale
>>> factor, addition is used instead.  See the attached script and figure
>>> for example.  In the example, it looks like the color scale goes from
>>> 0 to 2*5E3.  At least, that's what I thought when I first looked at
>>> it.  Instead it means 5000 to 5002.
>>>
>>> Is there anyway I can scale the colorbar labels by *multiplying* them
>>> by a scaling factor instead of *adding* a scaling factor?  That seems
>>> more intuitive to me and those I work with.
>>>
>>
>> Given the value range of 5000-5002, I doubt how using the scaling
>> factor improve your plot.
>>
>> To disable the use of offset (+5000),
>>
>> cb = fig.colorbar(pc)
>>
>> # do not use offset
>> cb.formatter.set_useOffset(False)
>>
>> cb.update_ticks()
>>
>> If you do want to use scaling factor,
>>
>> # to use scaling factor
>> cb.formatter.set_scientific(True)
>> cb.formatter.set_powerlimits((0,0))
>>
>> cb.update_ticks()
>>
>> This will only work with matplotlib v1.0.
>> In older versions, try to replace "update_ticks" with
>> "update_bruteforce" (but I'm not sure if this will work)
>>
>> IHTH,
>>
>
> Thanks for your suggestions.  I recognize that a range of 5000–5002 is
> not much; it was used simply to illustrate my point.
>
> I was able to turn the scaling off with set_useOffset(False).  Is
> there anyway to scale by multiplying instead of adding?
>
> Thanks,
> Jeremy
>