R: First derivative of the Ratio of First and Zeroth Order...

A1FirstDerivative {circular} | R Documentation

## First derivative of the Ratio of First and Zeroth Order Bessel Functions.

### Description

Evaluates the first derivative of the Ratio of First and Zeroth Order Bessel Functions

### Usage

      A1FirstDerivative(kappa)

### Arguments

`kappa` | non-negative numeric value at which to evaluate the first derivative of A1 function.

### Details

The formula (3.48) of Fisher (1993), pag. 52 is implemented. The function uses `A1` and `besselI`.

### Value

The value of the first derivative of A1 function in the point `kappa`.

### Author(s)

Claudio Agostinelli and Alessandro Gagliardi.

### References

N.I. Fisher (1993) Statistical Analysis of Circular Data, Cambridge University Press.

### See Also

`A1`, `besselI`, `A1inv`.

[Package circular version 0.4-93 Index]