Re: [Matplotlib-users] modifying colorbar ticklabels

[Eric F. <ef...@ha...>]

Jae-Joon Lee wrote:
> On Wed, Jan 20, 2010 at 12:12 PM, Mario Mech <me...@me...> wrote:
>> the smallest value (0.0) is labeled with "-0.0". I just want to get rid of the minus sign.
>>
> 
> This is because the actual value is "-9.00000000e-06" (this inherits
> from the levels of contour).

The reason for this fudge in contour is that contourf fills
lower < z <= upper
for each consecutive pair of contour levels.
When the minimum value of z coincides with the lowest level, then 
regions with that minimum are left blank; so the lowest level is 
adjusted downward slightly, making the lowest contour interval include 
the minimum value.

The fudge could be made optional via a kwarg, e.g.,
include_minimum=True (default) or False (to defeat the fudge).

This would not help Mario, though, assuming he is happy with the present 
contouring, and simply wants sane labeling of the 0-tick. For that, a 
Formatter adjustment is the simplest solution.

Eric