walk.r

f = function(weights,n){
  p = double(length(weights))
  position = sample(1:length(weights),1)
  p[position] = p[position] + 1
  for(i in 2:n){
    # determine candidate new position
    move = sample(c(-1,1),1)
    new_position = position + move
    
    if(new_position == 0 || new_position == length(weights)+1){
      p[position] = p[position] + 1
      next
    }
    
    # decide if you should move
    if(weights[position] < weights[new_position]){
      position = new_position
      p[position] = p[position] + 1
      next
    }
    if(weights[position] > weights[new_position]){
      should_move = (runif(1) < weights[new_position]/weights[position])
      if(should_move) position = new_position
      p[position] = p[position] + 1
      next
    }
  }
  print(weights)
  print(p)
  print(p/sum(p))
  print(weights/sum(weights))
}