CODEWITHSUNDEEP
pythonpandas
Michael Fleicher Tal
Michael Fleicher Tal

Reputation: 35

how to perform manipulations on categories on pandas DataFrame

I have a DataFrame of different time series of different experiments. each participant made several Trials of an experiment.

the data contains columns of some features. and I want to perform some analysis on some feature columns and update the data frame accordingly.

For example, I want to add column as mean of feature 1 of each trial and a column as shifted feature 1 of each trial.

this is what I have:

participant ID Trial Feature 1
1 1 2
1 1 4
1 2 1
1 2 3
2 1 4
2 1 6
2 2 2
2 2 6

This is what I want to get:

participant ID Trial Feature 1 mean of feature 1 feature 1 shifted
1 1 2 3 na
1 1 4 3 2
1 2 1 2 na
1 2 3 2 1
2 1 4 5 na
2 1 6 5 4
2 2 2 4 na
2 2 6 4 2

Upvotes: 0

Views: 27

Answers (1)

Anurag Dabas
Anurag Dabas

Reputation: 24314

Try via groupby(),transform() and shift():

df['mean of feature 1']=df.groupby(['participant ID','Trial'])['Feature 1'].transform('mean')
df['feature 1 shifted']=df.groupby(['mean of feature 1'])['Feature 1'].shift()

output of df:

   participant ID   Trial   Feature 1   mean of feature 1   feature 1 shifted
0       1               1           2           3               NaN
1       1               1           4           3               2.0
2       1               2           1           2               NaN
3       1               2           3           2               1.0
4       2               1           4           5               NaN
5       2               1           6           5               4.0
6       2               2           2           4               NaN
7       2               2           6           4               2.0

Upvotes: 1

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