theta.neville {elliptic} R Documentation

## Neville's form for the theta functions

### Description

Neville's notation for theta functions as per section 16.36 of Abramowitz and Stegun.

### Usage

theta.s(u, m, method = "16.36.6", ...)
theta.c(u, m, method = "16.36.6", ...)
theta.d(u, m, method = "16.36.7", ...)
theta.n(u, m, method = "16.36.7", ...)


### Arguments

 u Primary complex argument m Real parameter method Character string corresponding to A and S's equation numbering scheme ... Extra arguments passed to the method function, such as maxiter

### Author(s)

Robin K. S. Hankin

### References

M. Abramowitz and I. A. Stegun 1965. Handbook of mathematical functions. New York: Dover

### Examples

#Figure 16.4.
m <- 0.5
K <- K.fun(m)
Kdash <- K.fun(1-m)
x <- seq(from=0,to=4*K,len=100)
plot  (x/K,theta.s(x,m=m),type="l",lty=1,main="Figure 16.4, p578")
points(x/K,theta.n(x,m=m),type="l",lty=2)
points(x/K,theta.c(x,m=m),type="l",lty=3)
points(x/K,theta.d(x,m=m),type="l",lty=4)
abline(0,0)

#plot a graph of something that should be zero:
x <- seq(from=-4,to=4,len=55)
plot(x,(e16.37.1(x,0.5)-theta.s(x,0.5)),pch="+",main="error: note vertical scale")

#now table 16.1 on page 582 et seq:
alpha <- 85
m <- sin(alpha*pi/180)^2
## K <- ellint_Kcomp(sqrt(m))
K <- K.fun(m)
u <- K/90*5*(0:18)
u.deg <- round(u/K*90)
cbind(u.deg,"85"=theta.s(u,m))      # p582, last col.
cbind(u.deg,"85"=theta.n(u,m))      # p583, last col.



[Package elliptic version 1.4-0 Index]