Re: [Matplotlib-users] minus sign instead of hyphen in negative axes labels

[Michael D. <md...@st...>]

Forgot to attach example.  Sorry.

Michael Droettboom wrote:
> Presently, there's no direct way to do this.  matplotlib uses the 
> standard Python (derived from C) number formatting which uses a 
> hyphen.  There are a couple of workarounds, however.
>
> You can set a custom tick formatter by providing a function and 
> wrapping it in a FuncFormatter object.  (See attached).  You can have 
> your function replace all of the hyphens with minus signs, or force it 
> to use the mathtext formatting (which uses minus signs by default) by 
> wrapping the text in '$'.  Alternatively, if your plot is designed for 
> inclusion in t a (La)TeX document, you can turn usetex on in your 
> matplotlibrc.
>
> All that said, it might be nice to make this the default behavior in 
> future versions of matplotlib.  We're about to make a release, so I 
> don't want to put this in right now.  Could you possibly file a 
> "Feature Request" in the tracker so we don't lose track of this?
>
> Cheers,
> Mike
>
> Markus Kuhn wrote:
>> Matplotlib currently uses the "hyphen" character instead of a "minus
>> sign" when printing negative numbers in plots.
>>
>> While these two characters are traditionally not distinguished in
>> monospaced fonts, there is a big difference in proportional fonts. A
>> hyphen (Unicode character 0x002d) is very short and used between words,
>> whereas a minus sign (Unicode: 0x2212) is much longer and looks exactly
>> like the horizontal part of a plus sign.
>>
>> Practically all modern fonts do contain a minus sign. In those fonts
>> that still lack a minus sign, the (often slightly lower/thinner/longer)
>> "en dash" is usually a much less painful substitute than the hyphen.
>> [The PostScript standard encoding lacks a minus sign, but the PostScript
>> symbol font has one at 0x2d, as documented in
>> http://www.unicode.org/Public/MAPPINGS/VENDORS/ADOBE/symbol.txt ]
>>
>> Example:
>>
>> from pylab import *
>> plot([-3, -2, -1], [1,-3,-2])
>> title(u"wrong: -2..+2   correct: \u22122..+2")
>> show()
>>
>> Is there a way to cause matplotlib to use the correct minus-sign glyph?
>> That would help to keep typographically very picky editors of scientific
>> journals happy ...
>>
>> Markus
>>
>>   
>

-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA