filtering: Filter data before feeding som algorithm for gene expression...
In som: Self-Organizing Map

Filtering data by certain floor, ceiling, max/min ratio, and max - min difference.

1	filtering(x, lt=20, ut=16000, mmr=3, mmd=200)

`x`	a data frame or matrix of input data.
`lt`	floor value replaces those less than it with the value
`ut`	ceiling value replaced those greater than it with the value
`mmr`	the max/min ratio, rows with max/min < mmr will be removed
`mmd`	the max - min difference, rows with (max - min) < mmd will be removed