permTestCor {CarletonStats} R Documentation

## Permutation test for the correlation of two variables.

### Description

Hypothesis test for a correlation of two variables. The null hypothesis is that the population correlation is 0.

### Usage

```permTestCor(x, ...)

## Default S3 method:
permTestCor(x, y, B = 999, alternative = "two.sided",
plot.hist = TRUE, legend.loc = "topright", plot.qq = FALSE,
x.name = deparse(substitute(x)), y.name = deparse(substitute(y)),
...)

## S3 method for class 'formula'
permTestCor(formula, data, subset, ...)
```

### Arguments

 `x` a numeric vector. `...` further arguments to be passed to or from methods. `y` a numeric vector. `B` the number of resamples to draw (positive integer greater than 2). `alternative` alternative hypothesis. Options are `"two.sided"`, `"less"` or `"greater"`. `plot.hist` a logical value. If `TRUE`, plot the distribution of the correlations obtained from each resample. `legend.loc` location of the legend on the histogram. Options are `"topright"`, `"topleft"`, `"bottomleft"` and `"bottomright"`. `plot.qq` a logical value. If `TRUE`, plot the normal quantile-quantile plot of the correlations obtained from each resample. `x.name` Label for variable x `y.name` Label for variable y `formula` a formula `y ~ x` where `x, y` are numeric vectors. `data` a data frame that contains the variables given in the formula. `subset` an optional expression indicating what observations to use.

### Details

Perform a permutation test to test H_0: ρ = 0, where ρis the population correlation. The rows of the second variable are permuted and the correlation is re-computed.

The mean and standard error of the permutation distribution is printed as well as a P-value.

Observations with missing values are removed.

### Value

Returns invisibly a vector of the correlations obtained by the randomization.

### Methods (by class)

• `default`: Permutation test for the correlation of two variables.

• `formula`: Permutation test for the correlation of two variables.

Laura Chihara

### References

Tim Hesterberg's website: http://www.timhesterberg.net/bootstrap

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