## What changes were proposed in this pull request?
add R API for PrefixSpan
## How was this patch tested?
add test in test_mllib_fpm.R
Author: Huaxin Gao <huaxing@us.ibm.com>
Closes#21710 from huaxingao/spark-24207.
## What changes were proposed in this pull request?
Add a new section for fpm
Add Example for FPGrowth in scala and Java
updated: Rewrite transform to be more compact.
## How was this patch tested?
local doc generation.
Author: Yuhao Yang <yuhao.yang@intel.com>
Closes#17130 from hhbyyh/fpmdoc.