For what it is worth, we attacked this problem about four years ago at my
work. We just implemented a simple formatter. A locator can also be done
in a similar manner if that is desired.
This is not exactly is a perfect solution, but it worked really well for us.
class ScaledFormatter( ticker.Formatter ):
""": Takes an exisiting formatter and scales the value by a specified
amount.
"""
def __init__( self, scale, formatter ):
"""Initialize the scaled formatter.
= INPUT VARIABLES
- scale The scale factor to apply to the values specified by the
other formatter.
- formatter Another matplotlib formatter to use for formatting the
data labels.
"""
self.scale = scale
self.formatter = formatter
def __call__( self, x, pos = None ):
'Return the format for tick val x at position pos'
# get the string form of the value
valueStr = self.formatter( x, pos )
if len(valueStr) == 0:
return ''
# remove the unicode hyphen
valueStr = valueStr.replace( u'\u2212', '-' )
# convert to a float
value = float( valueStr )
# now scale the value
value *= self.scale
# convert ot a Unicode string
s = unicode( value )
# add the unicode hyphen
s.replace( '-', u'\u2212' )
return s
def set_locs( self, locs ):
'Make sure the encompassed formatter get these set.'
ticker.Formatter.set_locs( self, locs )
self.formatter.set_locs( locs )
def set_axis( self, axis ):
'Make sure the encompassed formatter get these set.'
ticker.Formatter.set_axis( self, axis )
self.formatter.set_axis( axis )
def set_view_interval( self, vmin, vmax ):
'Make sure the encompassed formatter get these set.'
ticker.Formatter.set_view_interval( self, vmin, vmax )
self.formatter.set_view_interval( vmin, vmax )
def set_data_interval( self, vmin, vmax ):
'Make sure the encompassed formatter get these set.'
ticker.Formatter.set_data_interval( self, vmin, vmax )
self.formatter.set_data_interval( vmin, vmax )
def set_bounds( self, vmin, vmax ):
'Make sure the encompassed formatter get these set.'
ticker.Formatter.set_bounds( self, vmin, vmax )
self.formatter.set_bounds( vmin, vmax )
--James
> -----Original Message-----
> From: Thomas Caswell [mailto:tcasw...@gmail.com]
> Sent: Thursday, May 23, 2013 5:26 PM
> To: matplotlib-devel@lists.sourceforge.net
> Subject: [matplotlib-devel] adding second formatter/locater set to axes
> objects
>
> A question I have seen go by twice on SO is how to add a tick marks to the
> top/right of a plot which are re-scaled version of the values on the
> bottom/lefit axis (ex km/h on the left and mph on the right). My
> understanding of the best way to do this is to use twin* and then keep the
> range of the two axes in sync by hand.
>
> I am proposing adding at set of alternate formatters/locators to the
`axis`
> objects which if they exist are used for the top/right labels.
> Before I dive too deep into this, I want to check that a) there isn't a
better
> way to do this that I do not know and b) if this sounds like a reasonable
> approach.
>
> Tom
>
> --
> Thomas Caswell
> tcasw...@gmail.com
>
>
----------------------------------------------------------------------------
--
> Try New Relic Now & We'll Send You this Cool Shirt New Relic is the only
SaaS-
> based application performance monitoring service that delivers powerful
full
> stack analytics. Optimize and monitor your browser, app, & servers with
just
> a few lines of code. Try New Relic and get this awesome Nerd Life shirt!
> http://p.sf.net/sfu/newrelic_d2d_may
> _______________________________________________
> Matplotlib-devel mailing list
> Matplotlib-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
------------------------------------------------------------------------------
Try New Relic Now & We'll Send You this Cool Shirt
New Relic is the only SaaS-based application performance monitoring service
that delivers powerful full stack analytics. Optimize and monitor your
browser, app, & servers with just a few lines of code. Try New Relic
and get this awesome Nerd Life shirt! http://p.sf.net/sfu/newrelic_d2d_may
_______________________________________________
Matplotlib-devel mailing list
Matplotlib-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/matplotlib-devel
