I asked another question earlier and I think I miswrote that question.
My older question is here Can I merge multiple linear regressions into one regression?
In the older question I was talking about splitting dataset into multiple subsets and putting them in 4 different models. and I got the answer for that one.
My question this time is a bit different
As my dataset is consists of multiple features, Like this
Y X1 X2 X3 X4
738 83 29 74 44
849 47 27 84 37
820 16 82 83 64
.
.
.
This dataset has 48,000 records
I have split this dataset into 4 different models So each model has 48,000 records with different features
Model 1 equation was $a_1 X_1 + b_1$
Model 1 equation was $a_2 X_2 + b_2$
Model 1 equation was $a_3 X_3 + b_3$
Model 1 equation was $a_4 X_4 + b_4$
Now I want to compile all 4 models into 1 model $Y_* = a_* X_{1,2,3,4} + b_*$
How can I achieve that?