Feature Transformation Techniques
Logarithmic transformation
- Use the logarithmic operation to compress the range of values and reduce skewness
- Log is essentially finding what the power is needed for the base to obtain the input
- Base 2: is finding what should be such that , so because
- Base 10: is finding what should be such that
- Base e or natural log: is finding what Y be such that
Square Root Transformation
- This technique reduces the range of values by taking the square root of each value. It is useful for stabilizing variance.
Box-Cox Transformation
- A family of power transformation