chi3 {CA3variants} | R Documentation |

## The partition of the Pearson three-way index

### Description

When three categorical variables are symmetrically related, we can analyse the strength of
the association using the three-way Pearson mean square contingency coefficient, named the chi-squared index.
The function `chi3`

partitions the Pearson phi-squared statistic when in `CA3variants`

we set the parameter `ca3type = "CA3"`

.

### Usage

```
chi3(f3, digits = 3)
```

### Arguments

`f3` |
The three-way contingency array given as an input parameter in CA3variants. |

`digits` |
The number of decimal digits. By default digits=3. |

### Value

The partition of the Pearson index into three two-way association terms and one three-way association term. It also shows the explained inertia, the degrees of freedom and p-value of each term of the partition.

### Author(s)

Rosaria Lombardo, Eric J Beh, Ida Camminatiello.

### References

Beh EJ and Lombardo R (2014) Correspondence Analysis, Theory, Practice and New Strategies. John Wiley & Sons.

Carlier A and Kroonenberg PM (1996) Decompositions and biplots in three-way correspondence analysis. Psychometrika, 61, 355-373.

### Examples

```
data(happy)
chi3(f3=happy, digits=3)
```

*CA3variants*version 3.3.1 Index]