Cannot use np.round or np.around on Float64Index

[hughesadam87]

np.round()/np.around() currently don't work on Flaot64Index, because the Float64Index is throwing an error when Float64Index.round() is called.

In our application, we are getting floating point digit discrepancies when doing subtraction and other floating point operations on these indicies, and I believe rounding would solve the problem.

Original mailing list thread:

https://groups.google.com/forum/#!topic/pydata/8aTLVKrPJfs

I'm using pandas.read_csv(), so I can't access the data apriori to it being written into a dataframe to round it before instantiation.

[jreback]

pls show exact code which is not working as well as pd.show_versions()

[shoyer]

np.around works for me using pandas 0.14.0 and numpy 1.8.1 on Python 2.7:

import numpy as np
import pandas as pd
idx = pd.Index(0.5 * np.arange(5))
print idx
print np.around(idx)

Float64Index([0.0, 0.5, 1.0, 1.5, 2.0], dtype='float64')
Float64Index([0.0, 0.0, 1.0, 2.0, 2.0], dtype='float64')

[hughesadam87]

Sorry if this issue appeared twice; doesn't seem to be showing up in my "created by you" list.

I was accidentally using a VE with pandas 0.13.1. It seems to have been corrected since. Here is the full error.

  In [1]: import numpy as np

  In [2]: import pandas as pd

  In [3]: idx = pd.Index(0.5 * np.arange(5))

  In [4]: print idx
  Float64Index([0.0, 0.5, 1.0, 1.5, 2.0], dtype='object')

  In [5]: print np.around(idx)
  ---------------------------------------------------------------------------
  AttributeError                            Traceback (most recent call last)
  <ipython-input-5-cd6106b80ffb> in <module>()
  ----> 1 print np.around(idx)

  /home/glue/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/numpy/core/fromnumeric.pyc in around(a, decimals, out)
     2609     except AttributeError:
     2610         return _wrapit(a, 'round', decimals, out)
  -> 2611     return round(decimals, out)
     2612 
     2613 

  AttributeError: rint

  In [6]: print np.round(idx)
  ---------------------------------------------------------------------------
  AttributeError                            Traceback (most recent call last)
  <ipython-input-6-69683a0affaf> in <module>()
  ----> 1 print np.round(idx)

  /home/glue/Enthought/Canopy_64bit/User/lib/python2.7/site-packages/numpy/core/fromnumeric.pyc in round_(a, decimals, out)
     2627     except AttributeError:
     2628         return _wrapit(a, 'round', decimals, out)
  -> 2629     return round(decimals, out)
     2630 
     2631 

  AttributeError: rint

[shoyer]

This is likely thanks to a change in how Float64Index is stored internally in 0.14: #6471

[hughesadam87]

Tight, thanks for the help