Normalize data with uneven groups?
I have a dataset with 3 independent variables [city, industry, amount] and wish to normalize the amount. But I wish to do it with respect to industry and city. Simply grouping by the city and industry gives me a lot of very sparse groups on which normalizing (min-max, etc.) wouldn't be very meaningful. Is there any better way to normalize it?
Topic preprocessing feature-scaling machine-learning
Category Data Science