Tilde Operator

## Description

R has a special operator, ~ to declare relationships between variables for a formula object. It either denotes the relationship between a response and explanatory variable. For example, to show that height of a plant is determined by light level, soil quality and amount of water you would write something similar to this code: height ~ light + soil + water

The operator can also be used to denote distribution in groups. This use of the operator is commonly seen in commands such as oneway.test or confint where multiple sets of data are passed to a function. We'll demonstrate this use in the sage cell.

## Sage Cell

This use of the operator tells R that each value in the data column in info is a part of either group 1 or group 2, depending on the group number in its row.

#### Code

``````info <- data.frame(data = c(2.1, 9.6, 2.9, 2.6, 6.8, 0.2, 4.6, 3.8, 4.7, 7.9, 8.9, 8.7, 1.1, 2.5, 3.5, 12.2, 5.2, 13.1, 12.9, 11.5),
group = c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2),
ID = c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10))
myFormula <- data ~ group
print(info)
print(myFormula)
NULL```
```

none

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