power.chisq.test {DescTools} | R Documentation |

## Power Calculations for ChiSquared Tests

### Description

Compute power of test or determine parameters to obtain target
power (same as `power.anova.test`

).

### Usage

```
power.chisq.test(n = NULL, w = NULL, df = NULL, sig.level = 0.05, power = NULL)
```

### Arguments

`n` |
total number of observations. |

`w` |
effect size. |

`df` |
degree of freedom (depends on the chosen test. |

`sig.level` |
Significance level (Type I error probability). |

`power` |
Power of test (1 minus Type II error probability). |

### Details

Exactly one of the parameters `w`

, `n`

, `power`

or
`sig.level`

must be passed as NULL, and this parameter is
determined from the others. Note that the last one has non-NULL
default, so `NULL`

must be explicitly passed, if you want to compute
it.

### Value

Object of class "power.htest", a list of the arguments (including the computed one) augmented with 'method' and 'note' elements.

### Note

`uniroot`

is used to solve power equation for unknowns, so you may
see errors from it, notably about inability to bracket the root
when invalid arguments are given.

### Author(s)

Stephane Champely <champely@univ-lyon1.fr>

but this is a mere copy of Peter Dalgaard's work on power.t.test

### References

Cohen, J. (1988) *Statistical power analysis for the
behavioral sciences (2nd ed.)* Hillsdale, NJ: Lawrence Erlbaum.

### See Also

### Examples

```
## Exercise 7.1 P. 249 from Cohen (1988)
power.chisq.test(w=0.289, df=(4-1), n=100, sig.level=0.05)
## Exercise 7.3 p. 251
power.chisq.test(w=0.346, df=(2-1)*(3-1), n=140, sig.level=0.01)
## Exercise 7.8 p. 270
power.chisq.test(w=0.1, df=(5-1)*(6-1), power=0.80, sig.level=0.05)
```

*DescTools*version 0.99.55 Index]