CODEWITHSUNDEEP
pythonpandasdataframe
prof31
prof31

Reputation: 85

How to find the difference of time series data points from the mean and create another column

I have time series data, I want to append a column that gives the difference between the value(x_i) and the mean(x_avg).

df
time    col1    newcolumn
1        30        0
2        20        -10
3        50        20
4        20       -10

where mean of col1 = (30+20+50+20)/4 = 30. thanks.

Upvotes: 0

Views: 25

Answers (1)

BehRouz
BehRouz

Reputation: 1364

You can use apply function. But you need to store the average of that column separately.

def diff(row):
    global mean
    return row.col1 - mean

dict = {'col1':[30,20,50,20]}
df = pd.DataFrame(dict)

mean = df.col1.mean()
df['diff'] = df.apply(diff, axis=1)

print(df)

   col1  diff
0    30   0.0
1    20 -10.0
2    50  20.0
3    20 -10.0

Upvotes: 1

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