Minimizing the distance between curves stacked on each other in R plot - r

Question

I have an R function that plots some curves stacked on top of each other (see picture below the code).
I was wondering, however, how I could adjust the distance between the curves (see blue arrows) so that the curves don't look so flat?
Also, is it possible to use polygon instead of lines to plot these curves?
stacked = function(a, b, lo, hi, d, Bi = 55, n = 1e2){
h = list()
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] = list(curve(posterior, ty = "n", ann = FALSE, yaxt = "n", xaxt = "n", add = i!= 1, bty = "n", n = 1e3))
}
plot(matrix(c(rep(c(.4, .8), each = length(d))), length(d), 2), rep(1:length(d), 2), ty = "n", xlim = 0:1, ann = FALSE, xaxt = "n", ylim = c(1, length(d)+.4))
for(i in 1:length(d)){
lines(h[[i]]$x, h[[i]]$y+i, ty = "l", xpd = NA, col = i)
}
}
# Example of use:
stacked(lo = 0, hi = 1, a = 2, b = 3, d = c("dgamma", "dnorm", "dcauchy", "dbeta", "dlogis", "dweibull"))

Answer 1

You can just scale the y-values before drawing the lines. I have added a scale parameter to your function. Try scale =2 or 3
stacked = function(a, b, lo, hi, d, Bi = 55, n = 1e2, scale=1){
h = list()
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] = list(curve(posterior, ty = "n", ann = FALSE, yaxt = "n", xaxt = "n", add = i!= 1, bty = "n", n = 1e3))
}
plot(matrix(c(rep(c(.4, .8), each = length(d))), length(d), 2), rep(1:length(d), 2), ty = "n", xlim = 0:1, ann = FALSE, xaxt = "n", ylim = c(1, length(d)+.4))
for(i in 1:length(d)){
lines(h[[i]]$x, scale*h[[i]]$y+i, ty = "l", xpd = NA, col = i)
}
}
stacked(lo = 0, hi = 1, a = 2, b = 3, scale=2,
d = c("dgamma", "dnorm", "dcauchy", "dbeta", "dlogis", "dweibull"))
If you wish to fill in the area under the curves, you can use polygon. Change the lines:
for(i in 1:length(d)){
lines(h[[i]]$x, scale*h[[i]]$y+i, ty = "l", xpd = NA, col = i)
}
TO
for(i in 1:length(d)){
polygon(x=h[[i]]$x, y=scale*h[[i]]$y+i, col = i)
}