Re: [Matplotlib-users] suggestion for tickmark labels

[Paul B. <ba...@st...>]

Darren Dale wrote:
> I was thinking about the way the labels are formatted. Some of the 
> numbers I work with are large(10^10) and small (10^-10), and the 
> formatting wasnt quite right. I am running the following as a test:
> 
> mport matplotlib
> from matplotlib.matlab import *
> from numarray import array
> 
> a=array(range(10))*1e6+1e7
> b = array(range(10))*1e-5+1e-4
> plot(a,b)
> 
> in ticker.py, in ScalarFormatter, what is the purpose of this routine?
> 
>        # if the value is just a fraction off an int, use the int
>        if abs(x-long(x))<0.0001*d:
>            if x<=10000: return '%d' % long(x + 0.5)
>            else: return '%1.0e'%long(x)
> 
> If commented out, the labels are formatted appropriately as 
> exponentials, otherwise, the level of precision can often not be useful. 
> Also, in the exponential formatting block, might this
> if d < 1e-3: fmt = '%1.3f'
> read this?:
> if d < 1e-2: fmt = '%1.3e'
> 
> One final suggestion, for formatting the exponential component:
> 
> m = self._zerorgx.match(s)
>        if m:
>            s = m.group(1)
>            if m.group(2) is not None:
> ##                 s += m.group(2)
>                s += m.group(2)[:2]+str(int(m.group(2)[2:])) ## my hack 
> to make 3e003 look like 3e3. (Whats the "right way"?)
>        s = s.replace('+', '')
>        return s
> 
> Darren

This patch has been committed, so exponential values should format correctly.

  -- Paul

-- 
Paul Barrett, PhD      Space Telescope Science Institute
Phone: 410-338-4475    ESS/Science Software Branch
FAX:   410-338-4767    Baltimore, MD 21218