loffset doesn't work in resample if used with agg()

[marcomayer]

Code Sample, a copy-pastable example if possible

# Create DF
df = pd.DataFrame(np.random.rand(5,2), columns=list('AB'), index=pd.date_range('2010-01-01 09:00:00', periods=5, freq='s'))

print(df)
                                       A                    B
2010-01-01 09:00:00             0.283113             0.559642
2010-01-01 09:00:01             0.754942             0.621557
2010-01-01 09:00:02             0.102002             0.892100
2010-01-01 09:00:03             0.885400             0.524359
2010-01-01 09:00:04             0.324761             0.706758

#Resample, loffset works fine using mean(), is offset by 2 hours.
print(df.resample('2s', loffset='2h').mean())
                                       A                    B
2010-01-01 11:00:00             0.519028             0.590599
2010-01-01 11:00:02             0.493701             0.708229
2010-01-01 11:00:04             0.324761             0.706758


# Resample with agg(), loffset doesn't work anymore.
print(df.resample('2s', loffset='2h').agg(dict(A='sum', B='mean')))
                                      A                    B
2010-01-01 09:00:00             1.038055             0.590599
2010-01-01 09:00:02             0.987402             0.708229
2010-01-01 09:00:04             0.324761             0.706758

Expected Output

I'd expect the same as with mean(), this is how resample worked in the past with resample(how=...).

But maybe I also misunderstood something about the change. If so please enlighten me.

Since I need this to keep things going, I use the following workaround for now, please let me know if this is the way to go or if there's a more efficient way:

print(df.resample('2s', loffset='2h').agg(dict(A='sum', B='mean')).tshift(2, 'h'))

output of pd.show_versions()

INSTALLED VERSIONS

commit: None
python: 3.5.1.final.0
python-bits: 64
OS: Darwin
OS-release: 15.5.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: de_DE.UTF-8

pandas: 0.18.1
nose: 1.3.7
pip: 8.1.2
setuptools: 20.3
Cython: 0.23.4
numpy: 1.10.4
scipy: 0.17.1
statsmodels: 0.6.1
xarray: None
IPython: 4.2.0
sphinx: 1.3.5
patsy: 0.4.0
dateutil: 2.5.1
pytz: 2016.2
blosc: None
bottleneck: 1.0.0
tables: 3.2.2
numexpr: 2.5.2
matplotlib: 1.5.1
openpyxl: 2.3.2
xlrd: 0.9.4
xlwt: 1.0.0
xlsxwriter: 0.8.4
lxml: 3.6.0
bs4: 4.4.1
html5lib: None
httplib2: None
apiclient: None
sqlalchemy: 1.0.12
pymysql: None
psycopg2: None
jinja2: 2.8
boto: 2.39.0
pandas_datareader: 0.2.1
In [92]:

[jreback]

hmm this was fixed for defined functions (e.g. .count/mean) in pydata#12757

prob not tested for aggregations; should be straightforward though.

want to do a pull-request?

[marcomayer]

I'd love to Jeff but I'm already back on schedule on my current project and will be busy for at least another half day to get all my stuff updated to work with 0.18.x - I'm a heavy resample() and rolling() user :/

[jreback]

@marcomayer no hurry :)

[marcomayer]

Okay I've put it on my todo-list ;)

[jreback]

gr8!