asecd computes the element-wise inverse secant of the argument, results in degree.

## Syntax

    y = asecd(x)

## Arguments

x

  Real or complex array

y

  Real or complex array

## Description

Computes the element-wise inverse secant of the argument, results in degree. For real input data with absolute value greater than `1` the results are real and in `[-90 90]`.

`asecd(x)` is equal to `asec(x)*180/%pi`.

## Sample

x=linspace(1,20,200); x=[-x($:-1:1) %nan x]; plot(x,asecd(x))

## Examples

    x=[1 2 -2 sqrt(2) -sqrt(2) 2/sqrt(3) -2/sqrt(3) -1];
    asecd(x)

## See also

- asec
- secd

## References

- Kahan, W., "Branch cuts for complex elementary functions, or, Much ado about nothing's sign bit", Proceedings of the joing IMA/SIAM conference on The State of the Art in Numerical Analysis, University of Birmingham, A. Iserles and M.J.D. Powell, eds, Clarendon Press, Oxford, 1987, 165-210.