# circ.cor1: Circular correlations between two circular variables In Directional: A Collection of R Functions for Directional Data Analysis

## Description

Circular correlations between two circular variables.

## Usage

 ```1 2 3``` ```circ.cor1(theta, phi, rads = FALSE) circ.cor2(theta, phi, rads = FALSE) ```

## Arguments

 `theta` The first cirular variable. `phi` The other cirular variable. `rads` If the data are expressed in rads, then this should be TRUE. If the data are in degrees, then this is FALSE.

## Details

circ.cor1: Correlation for circular variables using the cosinus and sinus formula of Jammaladaka and SenGupta (1988).

circ.cor2: Correlation for circular variables using the cosinus and sinus formula of Mardia and Jupp (2000).

## Value

A vector including:

 `rho` The value of the correlation coefficient. `p-value` The p-value of the zero correlation hypothesis testing.

## Author(s)

Michail Tsagris

R implementation and documentation: Michail Tsagris mtsagris@uoc.gr and Giorgos Athineou <gioathineou@gmail.com>

## References

Jammalamadaka, R. S. and Sengupta, A. (2001). Topics in circular statistics. World Scientific.

Jammalamadaka, S. R. and Sarma, Y. R. (1988) . A correlation coefficient for angular variables. Statistical Theory and Data Analysis, 2:349–364.

Mardia, K. V. and Jupp, P. E. (2000). Directional statistics. Chicester: John Wiley & Sons.

``` circlin.cor, circ.cor2, spml.reg ```

## Examples

 ```1 2 3 4``` ```y <- runif(50, 0, 2 * pi) x <- runif(50, 0, 2 * pi) circ.cor1(x, y, rads = TRUE) circ.cor2(x, y, rads = TRUE) ```

### Example output

```sh: 1: wc: Permission denied
Warning messages:
1: In rgl.init(initValue, onlyNULL) : RGL: unable to open X11 display
2: 'rgl.init' failed, running with 'rgl.useNULL = TRUE'.
rho      p-value
-0.003659608  0.979115389
rho   p-value
0.1193906 0.9497529
```

Directional documentation built on May 26, 2021, 5:07 p.m.