matplotlib-users

[Matplotlib-users] Format y-axis tick labels in 'comma' notation ie 234004 would be 234, 004 etc.

[Dharhas P. <Dha...@tw...>]

Hi All,

I'm assuming this is possible and common but I'm not finding the correct combination of search terms to find any examples on the mailing list or online on how to do this.

I'd like to display the y-axis tick labels in the 'comma' notation i.e.

234004 = 234,004
1237689 = 1,237,689
etc

thanks,

- dharhas

Re: [Matplotlib-users] Format y-axis tick labels in 'comma' notation ie 234004 would be 234, 004 etc.

[Gökhan S. <gok...@gm...>]

On Tue, Oct 19, 2010 at 1:31 PM, Dharhas Pothina
<Dha...@tw...> wrote:
> Hi All,
>
> I'm assuming this is possible and common but I'm not finding the correct combination of search terms to find any examples on the mailing list or online on how to do this.
>
> I'd like to display the y-axis tick labels in the 'comma' notation i.e.
>
> 234004 = 234,004
> 1237689 = 1,237,689
> etc
>
> thanks,
>
> - dharhas
>

Python 2.7 has format specifiers for thousands separation:

http://docs.python.org/dev/whatsnew/2.7.html#pep-378-format-specifier-for-thousands-separator

moneyfmt recipe http://docs.python.org/library/decimal.html#recipes
might provide an alternative solution. In any case you should need to
get yticklabels and set them with the converted values.


-- 
Gökhan

Re: [Matplotlib-users] Format y-axis tick labels in 'comma' notation ie 234004 would be 234, 004 etc.

[Friedrich R. <fri...@gm...>]

2010/10/19 Dharhas Pothina <Dha...@tw...>:
> I'm assuming this is possible and common but I'm not finding the correct combination of search terms to find any examples on the mailing list or online on how to do this.
>
> I'd like to display the y-axis tick labels in the 'comma' notation i.e.
>
> 234004 = 234,004
> 1237689 = 1,237,689

You could write your own formatter, don't be scared.  The following
might be a good starting point:
http://matplotlib.sourceforge.net/api/ticker_api.html#matplotlib.ticker.FuncFormatter

You just need to write a function inserting the comma into the
number's string repr() given a plain Python number.

If I'm not mistaken this feature has never been requested so far, AFAICT.

Just got Goekhan's message, try a combination of both, might be worth.

hthy,
Friedrich

Re: [Matplotlib-users] Format y-axis tick labels in 'comma' notation ie 234004 would be 234, 004 etc.

[Dharhas P. <Dha...@tw...>]

> Just got Goekhan's message, try a combination of both, might be worth.

a little inelegant but I got it working by combining both ideas:

def thousands(x, pos):
    'The two args are the value and tick position'
    xnew = moneyfmt(Decimal(x.__str__()))
    return xnew

where moneyfmt is the function defined in Gokhan's link.

and then:

formatter = FuncFormatter(thousands)
...
ax1.yaxis.set_major_formatter(formatter)

thanks

- d

Re: [Matplotlib-users] Format y-axis tick labels in 'comma' notation ie 234004 would be 234, 004 etc.

[Dharhas P. <Dha...@tw...>]

> There's no way around the ``Decimal``?  Otherwise I cannot confirm the
> inelegancyness except this construct ;-)

the moneyfmt routine I downloaded requires the Decimal package (i.e decimal.Decimal). I didn't have time to try writing my own version. It has a bug that if you specify number of decimal places = 0 it shows the trailing decimal point.

- dharhas

Re: [Matplotlib-users] Format y-axis tick labels in 'comma' notation ie 234004 would be 234, 004 etc.

[Friedrich R. <fri...@gm...>]

Hi Dharhas,

2010/10/19 Dharhas Pothina <Dha...@tw...>:
>> There's no way around the ``Decimal``?  Otherwise I cannot confirm the
>> inelegancyness except this construct ;-)
> the moneyfmt routine I downloaded requires the Decimal package (i.e decimal.Decimal). I didn't have time to try writing my own version. It has a bug that if you specify number of decimal places = 0 it shows the trailing decimal point.

Is there a specific reason to not use py2.7, as suggested by Goekhan?
I would not bet my life that it's possible without any problems, but
if, then the new format specification seems much better then the
clumsy Decimal "workaround".

I just ran across this while informing myself about py2.7.

Hmm ... I see there is no binary for py2.7 (today), so you'd have to
compile it yourself.  Might be kind of a problem if you're using
Windows.

Friedrich