Reputation: 666
When I'm using prophet with growth == 'logistic'
I get the following error
k initialized to invalid value (-nan)
After a little debug I found the issue.
The issue raises in case the y
of the minimum date is half of the y
max, and the df['cap_scaled'] == 1
.
the following line assigns 2
into r0
r0 = max(1.01, df['cap_scaled'].ix[i0] / df['y_scaled'].ix[i0])
and this line assigns 0
into L0
L0 = np.log(r0 - 1)
this line assigns 0
into m
m = L0 * T / (L0 - L1)
and this line divides by zero
k = L0 / m
How should I fix this?
The workaround I thought about is to subtract or add epsilon to the y
in the min date. Is it a good one?
Upvotes: 1
Views: 166