Original

set.seed(1001) # setting the random number generator
L <- 30 # maximum range
nparents <- 50 # number of starting parents
offspr_per_parent <- 10 # yup
noffspr <- nparents * offspr_per_parent # total offspring
dispdist <- 2 # dispersal distance

parent_x <- runif(nparents, min = 0, max = L) # parent x value from uniform distribution
parent_y <- runif(nparents, min = 0, max = L) # parent y value from uinform distribution

angle <- runif(noffspr, min = 0, max = 2 * pi) # angle of dispersal from uniform distribution
dist <- rexp(noffspr, 1/dispdist) # distance of dispersal from exponential distribution (fixed distance?)

offspr_x <- rep(parent_x, each = offspr_per_parent) + cos(angle) * dist # offspring x location: repeat parent x value for each offspring + cosine angle times distance
offspr_y <- rep(parent_y, each = offspr_per_parent) + sin(angle) * dist # same as before

pos <- cbind(offspr_x, offspr_y) # binding the x and y values together
ndist <- as.matrix(dist(pos, upper = TRUE, diag = TRUE)) # distance to the nearest neighbor
nbrcrowd <- rowSums(ndist < 2) - 1 # number of things that crowd out the focal individual

ci <- nbrcrowd * 3 # crowding times 3
m <- 2.3
alpha <- 0.49
Mass_det <- m/(1+ci) # threshold is 2.3
Mass <- rgamma(length(Mass_det), scale = Mass_det, shape = alpha) # return a mass value from gamma distribution

b <- 271.6
k <- 0.569
seed_det <- b * Mass # mean for the binomial
seed = rnbinom(length(seed_det), mu = seed_det, size = k) # binomial distribution of the seed size (integer values centered at mu)


# We would need to add a separate system for the fungi and an interaction so they would be antagonistic