I am a bit confused on the size of the SOM grid size suggested by Vesanto.
Here in this link, it says
5*sqrt(N) where N is mentioned as the dataset size. What is meant by dataset size? the number of observations (rows)? number of dimensions (columns)? or product of the two?
And here also there is a mention of it, but the instructions are not clear.
could somebody clarify what is meant by N?