Thanks Jeremy, I think I misunderstood, so does it mean the set_rf_sampels following these lines of code (which does the split_vals to create train and valid ) only does sampling from the X_train data set , is that correct , if thats the case it makes sense to me.
df_trn, y_trn, nas = proc_df(df_raw, ‘SalePrice’)
X_train, X_valid = split_vals(df_trn, n_trn)
y_train, y_valid = split_vals(y_trn, n_trn)
Thanks for taking the time to reply, appreciate it.