some question about the spark-fm

[hugstone]

Q1. compare with the https://github.com/Intel-bigdata/imllib-spark，the auc performance of this spark-fm is very bad in my ctr prediction task, i have try mini-batch SGD、L-BFGS、parallel SGD and parallel FTRL, all auc < 0.7，but the same dataset and parameters on imllib-spark is 0.88，is there some fault in the implementation? Q2. in my opinion, optimizer FTRL is not a good method in FM optimize task，because ftrl will lead to the matrix V is sparse，which will recduce the effect of cross features.