#functions for Parallel Simulations Research Profile

comb <- function(...) {
  mapply('cbind', ..., SIMPLIFY=FALSE)
}


rwalk  <- function(n.org, time, stepsize = 0, prob = 0.5, plot = TRUE, title = "name", radius = 300){    
  require(ggplot2)
  
  whereto  <-  matrix(ncol = 2)       #creates matrix to store data in
  
  for(x in 1:n.org){
    walker  <-  matrix(c(0,0), nrow = time + 1, ncol = 2, byrow = T)   #creates matrix of x,y coordinants
    
    for(i in 1:time){ 
      
      #calculating it in polar cordinants
      # Stepsize
      step <- stepsize
      
      # Movement
      direction  <- runif(1, 0, 360)
      
      #conversion constant 
      #pi = 180 degrees 
      conversion = pi/180
      
      #random radian angle
      radian  <- direction * conversion 
      
      
      #Conversion from polar coordinants to cartesian plane
      
      xspot  <- step* cos(radian)
      yspot  <- step* sin(radian)
      
      #adding those coordinants to our last ones
      
      walker[i+1, 1] <- walker[i,1] + xspot
      walker[i+1, 2] <- walker[i,2] + yspot
      
    }
    
    whereto <- rbind(whereto, walker)
  }
  
  id <- rep(1:n.org, each = time +1)
  colnames(whereto) <- c("x" , "y")
  whereto <- as.data.frame(whereto)
  whereto <- cbind(whereto[2:nrow(whereto),], org = factor(id))          #binds the two matricies together
  
  if(plot){
    require(ggplot2)
    p <- ggplot(whereto, aes(x = x, y = y, colour = org))
    p <- p + geom_path() + 
      ggtitle(title) + 
      theme(legend.position="none") +
      annotate("path",                                     #specifies the path of the vemco circle
               x=0+radius*cos(seq(0,2*pi,length.out=100)), #x positions
               y=0+radius*sin(seq(0,2*pi,length.out=100))) + #y positions
      annotate("text",
               x = radius, 
               y = radius, 
               label = "Vemco Detection Radius")
    print(p)
  }
  
  return(whereto)
  
}


dfresults <- function(listname, listnum, IDcol =ID) { 
  l<-eval(parse(text = paste(listname, "[", listnum, "]", sep = ""))) #pulls the list
  
  d <- data.frame(l)   #turns it into dataframe
  
  rd <- NULL
  rd$x <- stack(d[str_detect(names(d), "x")])$values
  rd$y <- stack(d[str_detect(names(d), "y")])$values
  rd$org <- as.factor(IDcol)
  rd <- data.frame(rd)
  
  return(rd)
}