Question: Restrict Columns Involved with Interaction

[AllardJM]

Is there a way or a work-around to run a FM on a standard regression type data set but only allow the factorized interaction between certain column sets? For example only allow interactions between column A and columns B through Z?

[ibayer]

@AllardJM That's currently not implemented, but excluding certain columns from the second order interactions shouldn't be to complicated to do. What's you motivation?

For the ALS/CD solver the following hack would be possible (let's assume you want to exclude column A):

• set the initial values for column A to zero
• never update the value in column A (skip p==A in https://github.com/ibayer/fastFM-core/blob/master/src/ffm_als_mcmc.c#L173 )