In statistics, data transformation refers to the application of a deterministic mathematical function to each point in a data set.
- is the data point at time t
- is the transformed data point at time t
- is the transform function
- Nearly always, the function that is used to transform the data is invertible and generally continuous.
- Depending on the values of the sample data, several different algorithms might be used:
- Positive values: Logarithmic or square root Excel transformation
- Non-zero values: Multiplicative inverse Excel transformation
- Non-negative values: Power Excel transformation can be used.
- The power Excel transformation is a family of Excel transformations parametrized by a non-negative value ()that includes logarithm, square root, and multiplicative inverse as special cases.