I am using a dataset composed by $m$ samples and $n$ features (genes). Each data point is real number.
I want to understand how to preprocess data before analysis, in particular: do data points follow a normal or a log-normal distribution?
I thought about using qqplots and searching for different tests to assess the form of the distribution, but I have a doubt:
Do I have to assess the form of:
- each sample distribution
- each feature (gene) distribution
- the whole dataset ($m$ samples x $n$ features (genes))