# How do I transform a variable in SAS?

## How do I transform a variable in SAS?

Simple Transformations

- Log — Variable is transformed by taking the natural log of the variable.
- Square Root — Variable is transformed by taking the square root of the variable.
- Inverse — Variable is transformed by using the inverse of the variable.
- Square — Variable is transformed by using the square of the variable.

### What is transform variable?

Variable transformation is a way to make the data work better in your model. Data variables can have two types of form: numeric variable and categorical variable, and their transformation should have different approaches. – Numeric Variable Transformation: is turning a numeric variable to another numeric variable.

**What is SAS transformation?**

The transformation enables you to include that task in a SAS Data Integration Studio job flow. A transformation is a metadata object that specifies how to extract data, transform data, or load data into data stores. Each transformation that you specify in a process flow diagram generates or retrieves SAS code.

**How do you log transform a variable in SAS?**

To perform a log transformation in SAS requires one argument as input into the log function. Most commonly, the argument supplied is the name of the variable. You can also specify a numeric constant or expression, aside from a variable. Second, the argument must be a positive numeric constant, variable or expression.

## Why do we transform variables?

Transformation is a mathematical operation that changes the measurement scale of a variable. This is usually done to make a set of useable with a particular statistical test or method. Many statistical methods require data that follow a particular kind of distribution, usually a normal distribution.

### What does data transformation mean?

Data transformation is the process of changing the format, structure, or values of data. For data analytics projects, data may be transformed at two stages of the data pipeline. Processes such as data integration, data migration, data warehousing, and data wrangling all may involve data transformation.

**How do you do log transformation in SAS?**

**What is square root transformation?**

a procedure for converting a set of data in which each value, xi, is replaced by its square root, another number that when multiplied by itself yields xi. Square-root transformations often result in homogeneity of variance for the different levels of the independent variable (x) under consideration.

## What are the methods for transforming categorical variables?

Below are the methods to convert a categorical (string) input to numerical nature:

- Label Encoder: It is used to transform non-numerical labels to numerical labels (or nominal categorical variables).
- Convert numeric bins to number: Let’s say, bins of a continuous variable are available in the data set (shown below).

### How to convert a character variable to a SAS date?

If it is a character variable, you can convert it to a SAS date so that you can take advantage of the SAS date functions. Look at the date informats to determine which informat matches your values. In this case, DATE9. reads date values in the form ddmmmyy, which matches 12JUL2016.

**What do you need to know about format in SAS?**

The format tells SAS what format to apply to the value in the original variable. The format must be of the same type as the original variable. For example, if you are using the PUT function to convert a numeric value to character, the format must be a numeric format.

**How is the Box Cox transformation used in SAS?**

SAS has implemented the Box Cox transformation for regression in PROC TRANSREG. In this procedure the optimal λ is chosen, the data is transformed, and the regression model is fit. In this implementation, the transformation is limited to the dependent variable in the model.

## How are variables transformed in a transform statement?

With a TRANSFORM statement, variables are transformed before the imputation process, and these transformed variable values are displayed in all of the results. When you specify an OUT= option, the variable values are back-transformed to create the imputed data set.