colorbar.Colorbar ticking

Community matplotlib-users
#1

2010/3/29 Eric Firing <efiring@...202...>:

It already has this. You can pass in a custom locator or set of tick
locations via the "ticks" kwarg, but if you don't, a locator is chosen
automatically. Except in special cases, this will be a MaxNLocator. See the
ColorbarBase._ticker method.

Ah, thanks, It escaped my notice that there is a toplevel "if
self.locator is None:" statement ... ok.

Ah, maybe what you mean is a text option to the "ticks" kwarg that would
specify MaxNLocator without requiring one to instantiate a MaxNLocator? I
don't think this makes sense for the case when boundaries are specified
explicitly.

No, what I intended is exactly what you pointed out.

Btw, can you tell me what the *values* kwarg's semantic is? I guess,
it shall be the center values of the values displayed, but then the
implementation for this in ColorbarBase._process_values() would be
broken.

Friedrich

P.S.: I assume you have be caught by the "misconfiguration" of the
list that the sender is used as the default recipient, so I post back
to the list?

#2

Friedrich Romstedt wrote:

2010/3/29 Eric Firing <efiring@...202...>:

It already has this. You can pass in a custom locator or set of tick
locations via the "ticks" kwarg, but if you don't, a locator is chosen
automatically. Except in special cases, this will be a MaxNLocator. See the
ColorbarBase._ticker method.

Ah, thanks, It escaped my notice that there is a toplevel "if
self.locator is None:" statement ... ok.

Ah, maybe what you mean is a text option to the "ticks" kwarg that would
specify MaxNLocator without requiring one to instantiate a MaxNLocator? I
don't think this makes sense for the case when boundaries are specified
explicitly.

No, what I intended is exactly what you pointed out.

Btw, can you tell me what the *values* kwarg's semantic is? I guess,
it shall be the center values of the values displayed, but then the
implementation for this in ColorbarBase._process_values() would be
broken.

The ColorbarBase simply makes a strip of colored blocks, with their sizes and locations determined by the boundaries kwarg (together with the "spacing" kwarg) and their colors determined from the values kwarg via color mapping. If either or both of these kwargs is None, the boundaries and/or values will be generated in _process_values. The use of the non-default values kwarg is illustrated by the special-case handling of colorbars for contouring in the Colorbar class.

Can you give a test case showing a problem with _process_values?

Friedrich

P.S.: I assume you have be caught by the "misconfiguration" of the
list that the sender is used as the default recipient, so I post back
to the list?

The mpl lists have been unusual (at least compared to lists for numpy, scipy, and cython) in this respect for years. Usually I remember to reply to all, but you are right--this time I goofed.

Eric