All,
My dataset looks like following. I am trying to predict the 'amount' for next 6 months using either the fbProphet
or other model. But my issue is that I would like to predict amount based on each groups i.e A,B,C,D for next 6 months. I am not sure how to do that in python
using fbProphet
or other model ? I referenced official page of fbprophet, but the only information I found is that "Prophet" takes two columns only One is "Date" and other is "amount" .
I am new to python, so any help with code explanation is greatly appreciated!
import pandas as pd
data = {'Date':['2017-01-01', '2017-02-01', '2017-03-01', '2017-04-01','2017-05-01','2017-06-01','2017-07-01'],'Group':['A','B','C','D','C','A','B'],
'Amount':['12.1','13','15','10','12','9.0','5.6']}
df = pd.DataFrame(data)
print (df)
output:
Date Group Amount
0 2017-01-01 A 12.1
1 2017-02-01 B 13
2 2017-03-01 C 15
3 2017-04-01 D 10
4 2017-05-01 C 12
5 2017-06-01 A 9.0
6 2017-07-01 B 5.6
fbprophet
requires two columns ds
and y
, so you need to first rename the two columns
df = df.rename(columns={'Date': 'ds', 'Amount':'y'})
Assuming that your groups are independent from each other and you want to get one prediction for each group, you can group the dataframe by "Group" column and run forecast for each group
from fbprophet import Prophet
grouped = df.groupby('Group')
for g in grouped.groups:
group = grouped.get_group(g)
m = Prophet()
m.fit(group)
future = m.make_future_dataframe(periods=365)
forecast = m.predict(future)
print(forecast.tail())
Take note that the input dataframe that you supply in the question is not sufficient for the model because group D only has a single data point. fbprophet
's forecast needs at least 2 non-Nan rows.
EDIT: if you want to merge all predictions into one dataframe, the idea is to name the yhat
for each observations differently, do pd.merge()
in the loop, and then cherry-pick the columns that you need at the end:
final = pd.DataFrame()
for g in grouped.groups:
group = grouped.get_group(g)
m = Prophet()
m.fit(group)
future = m.make_future_dataframe(periods=365)
forecast = m.predict(future)
forecast = forecast.rename(columns={'yhat': 'yhat_'+g})
final = pd.merge(final, forecast.set_index('ds'), how='outer', left_index=True, right_index=True)
final = final[['yhat_' + g for g in grouped.groups.keys()]]