RWalk: Demographic noise

In herrmannrobert/VerDi: Modelling the vertical distribution of aquatic organisms

Description

Function generates random walk (demographic noise) based on a normal distribution (ND) or uniform distribution (UD).

Usage

RWalk(par, hs = 0.1, mv = 0, sd = 0.1, min = -0.2, max = 0.2,
  op = "ND")

Arguments

par	numeric vector or R object.
hs	numeric, half saturation parameter, Default: 0.1
mv	numeric, mean when op = "ND", Default: 0
sd	numeric, standard deviation when op = "ND", Default: 0.1
min	numeric, minimum value when op = "UD", Default: -0.2
max	numeric, maximum value when op = "UD", Default: 0.2
op	character, either 'ND' (normal distribution) or 'UD' (uniform distribution), Default: 'ND'

Details

Is used to add demograhic noise (random walk) to e.g. the population's vertical distribution. Further details in rnorm() and runif().

Examples

## Not run: 

#Example shows difference between options (op)
#Variables (hs, mv, sd, min, max) are set to default (see description above)

rw <- data.frame()

set.seed(123)
for(i in 1:100){
 rw[i,1] <- RWalk(0)
 rw[i,2] <- RWalk(0, op = "UD")
 
 if(i == 100){colnames(rw) <- c("Normally distributed random walk", "Uniformly distributed random walk")
 
  par(mfrow = c(2, 2))
  plot(rw[,1], type = "l", main = colnames(rw)[1], ylab = "Random walk", xlab = "", ylim = c(-0.4, 0.4))
  plot(rw[,2], type = "l", main = colnames(rw)[2], ylab = "", xlab = "", ylim = c(-0.4, 0.4))
  hist(rw[,1], breaks = 100, main = "", xlab = "", xlim = c(-0.4, 0.4), ylim = c(0, 14))
  lines(density(rw[,1], adjust=2), lwd = 2)
  hist(rw[,2], breaks = 100, main = "", ylab = "", xlab = "", xlim = c(-0.4, 0.4), ylim = c(0, 14))
  lines(density(rw[,2], adjust=2), lwd = 2)
  }
  
 }

## End(Not run)

herrmannrobert/VerDi documentation built on June 10, 2019, 7:32 a.m.