# t1waybt: Bootstrap version of the heteroscedastic one-way ANOVA for... In WRS2: A Collection of Robust Statistical Methods

## Description

Test the hypothesis of equal trimmed means using a percentile t bootstrap method. Corresponding post hoc tests are provided in `mcppb20`.

## Usage

 ```1 2``` ```t1waybt(formula, data, tr = 0.2, nboot = 599, ...) mcppb20(formula, data, tr = 0.2, nboot = 599, ...) ```

## Arguments

 `formula` an object of class formula. `data` an optional data frame for the input data. `tr` trim level for the mean. `nboot` number of bootstrap samples. `...` currently ignored.

## Value

Returns an object of class `t1waybt` containing:

 `test` value of the test statistic `p.value` p-value `Var.Explained` explained amount of variance `Effect.Size` effect size `nboot.eff` effective number of bootstrap samples `call` function call

`mcppb20` returns an object of class `"mcp1"` containing:

 `comp` inference for all pairwise comparisons `fnames` names of the factor levels

## References

Wilcox, R. (2012). Introduction to Robust Estimation and Hypothesis Testing (3rd ed.). Elsevier.

`t1way`,`med1way`

## Examples

 ```1 2 3 4``` ```t1waybt(libido ~ dose, data = viagra) ## post hoc mcppb20(libido ~ dose, data = viagra) ```

### Example output

```Call:
t1waybt(formula = libido ~ dose, data = viagra)

Effective number of bootstrap samples was 387.

Test statistic: 3
p-value: 0.12403
Variance explained 0.623
Effect size 0.789

Warning message:
In t1waybt(libido ~ dose, data = viagra) :
Some bootstrap estimates of the test statistic could not be computed.
Call:
mcppb20(formula = libido ~ dose, data = viagra)

psihat ci.lower ci.upper p-value
placebo vs. low      -1 -3.00000  1.33333 0.34558
placebo vs. high     -3 -5.00000 -0.33333 0.00334
low vs. high         -2 -4.33333  0.66667 0.11018
```

WRS2 documentation built on July 20, 2021, 9:06 a.m.