If a value is exactly equal to the mean of all the values of the feature, it will be normalized to 0. If it is below the mean, it will be a negative number, and if it is above the mean it will be a positive number.
How do you scale negative data?
Find the largest positive number and the smallest (most negative) number in the array. Add the absolute value of the smallest (most negative) number to every value in the array. Divide each result by the difference between the largest and the smallest number.
When should you not use normalization?
Some Good Reasons Not to Normalize
- Joins are expensive. Normalizing your database often involves creating lots of tables. ...
- Normalized design is difficult. ...
- Quick and dirty should be quick and dirty. ...
- If you're using a NoSQL database, traditional normalization is not desirable.
