rnorouzian rnorouzian - 4 days ago 4
R Question

How to make `integrate()` to accept a vector in an R function?

I am wondering how I could make my function

BPP
to accept a vector for its first argument
t
?

Bpp = function(t, n1, n2 = NULL){

N = ifelse(is.null(n2), n1, n1*n2/(n1+n2))
df = ifelse(is.null(n2), n1 - 1, n1 + n2 - 2)

H1 = integrate(function(delta)dcauchy(delta, 0, sqrt(2)/2)*dt(t, df, delta*sqrt(N)), -Inf, Inf)[[1]]
H0 = dt(t, df)
BF10 = H1/H0
p.value = 2*(1-pt(abs(t), df))

list(BF10 = BF10, p.value = p.value)
}

Bpp(t = -6:6, 20, 20) ## This will give error because `t` is now a vector?

Answer

Looks like I could give a quick answer without testing. Use the following in your BPP:

# joint density
joint <- function(delta, t) dcauchy(delta, 0, sqrt(2)/2) * dt(t, df, delta*sqrt(N))
# marginal density of `t`
marginal.t <- function (t) integrate(joint, lower = -Inf, upper = Inf, t = t)[[1]]
H1 <- sapply(t, marginal.t)