Saving x, and y from `curve()` in a for loop R? - r

Question

I have a function called all.priors (see R code below). My goal is to get the x and y from the curve() call inside the for loop, and save these xs and ys as object h.
(I want to have 101 rows, and 2*length(d) columns in h. This way, each 2 columns, contain x and y from a curve() run in the for loop.)
Question:
how can I correctly save the xs and ys from the curve() call? [I get the error: incorrect number of subscripts on matrix]
all.priors = function(a, b, lo, hi, d, Bi = 55, n = 1e2){
h = matrix(NA, 101, 2*length(d))
for(i in 1:length(d)){
p = function(x) get(d[i])(x, a, b)
prior = function(x) p(x)/integrate(p, lo, hi)[[1]]
likelihood = function(x) dbinom(Bi, n, x)
posterior = function(x) prior(x)*likelihood(x)
h[i,] = curve(posterior, ty = "n", ann = FALSE, yaxt = "n", xaxt = "n", add = i!= 1, bty = "n")
}
}
#Example of use:
all.priors(lo = 0, hi = 1, a = 2, b = 3, d = c("dgamma", "dnorm", "dcauchy", "dlogis"))

Answer 1

You just need to carefully place the values in the matrix, and then return the matrix from your function. try this
all.priors = function(a, b, lo, hi, d, Bi = 55, n = 1e2){
h = matrix(NA, 101, 2*length(d))
for(i in 1:length(d)){
p = function(x) get(d[i])(x, a, b)
prior = function(x) p(x)/integrate(p, lo, hi)[[1]]
likelihood = function(x) dbinom(Bi, n, x)
posterior = function(x) prior(x)*likelihood(x)
cv <- curve(posterior, ty = "n", ann = FALSE, yaxt = "n", xaxt = "n", add = i!= 1, bty = "n")
h[,i*2-1] <- cv$x
h[,i*2] <- cv$y
}
h
}
all.priors(lo = 0, hi = 1, a = 2, b = 3, d = c("dgamma", "dnorm", "dcauchy", "dlogis"))

Answer 2

A different way to solve this might be to save the answers in a list rather than a matrix. I think that your function complicates the picture of what is going on, so I will use a simpler example.
h = list()
for(i in 1:5) {
h[i] = list(curve(sin(i*x), xlim=c(0,6.3))) }
The resulting data structure should be easy to use.