What is the use of tilde operator (~) in R?

R ProgrammingServer Side ProgrammingProgramming

Tilde operator is used to define the relationship between dependent variable and independent variables in a statistical model formula. The variable on the left-hand side of tilde operator is the dependent variable and the variable(s) on the right-hand side of tilde operator is/are called the independent variable(s). So, tilde operator helps to define that dependent variable depends on the independent variable(s) that are on the right-hand side of tilde operator.

Example

> Regression_Model <- lm(y~ x1 + x2 + x3)

Here, the object Regression_Model stores the formula for linear regression model created by using function lm and y is the dependent variable and x1, x2, and x3 are independent variables.

This model can be created by using a dot (.) if we want to include all the independent variables but for this purpose, we should have all the variables stored in a data frame.

Example

> Regression_Data <- data.frame(x1, x2, x3, y)
> Regression_Model_New < - lm(y~ . , data = Regression_Data)

This will have the same output as the previous model, but we cannot use tilde with dot if we want to create a model with few variables.

Suppose you want to create a new model with x1 and x3 only then it can be done as follows −

> Regression_Model_New1 <- lm(y~ x1 + x3, data = Regression_Data)

But we cannot do it using dot with tilde as −

> Regression_Model_New2_Incorrect <- lm(y~ . + x3, data = Regression_Data)

https://www.tutorialspoint.com/how-to-write-text-and-output-it-as-a-text-file-using-r

raja
Published on 06-Jul-2020 14:56:13
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