edge <- matrix(NA, nbr, 2)
## coalescence times by default:
x <- if (is.character(br)) 2*rexp(n - 1)/(as.double(n:2) * as.double((n - 1):1))
edge <- matrix(NA, nbr, 2)
## coalescence times by default:
x <- if (is.character(br)) 2*rexp(n - 1)/(as.double(n:2) * as.double((n - 1):1))