View source for Data transformation (statistics)

In [[statistics]], '''data transformation''' is the application of a deterministic mathematical function to each point in a data set — that is, each data point zi is replaced with the transformed value yi = f(zi), where f is a function.

== Description ==

Transforms are usually applied so that the data appear to more closely meet the assumptions of a [[statistical inference]] procedure that is to be applied, or to improve the interpretability or appearance of [[Statistical graphics|graphs]].


Nearly always, the function that is used to transform the data is invertible, and generally is continuous.

The transformation is usually applied to a collection of comparable measurements. For example, if we are working with data on peoples' incomes in some currency unit, it would be common to transform each person's income value by the [[logarithm]] function.

== See also ==

* [[Arcsin]] (transformation, for example, for [[Pearson correlation coefficient]])
* [[Logit]]
* [[Power transform (box-cox)]]
* [[Statistical inference]]
* [[Statistics]]

== External links ==

* [https://en.wikipedia.org/wiki/Data_transformation_(statistics) Data transformation (statistics)] @ Wikipedia.org 

[[Category:Statistics]]