R/LatCentroid.R

In LewisAJones/LBGSim: Latitudinal biodiversity gradient simulator

#' Generates latitudinal centroid for each Hemisphere.
#' 
#' @param f Dataframe (colnames:x, y, p). A dataframe containing latitudinal bin midpoint (x), species richness (y), and centroid weights (p).
#' @return Occurrence frequency distribution of species (dataframe and plot). If reps is FALSE, occurrences counts for each species given in each bin returned. If reps is TRUE, the same as FALSE but mean counts, standard deviation, n, and 95 percent confidence intervals.
#' @importFrom sp SpatialPointsDataFrame
#' @importFrom spatialEco wt.centroid
#' @export

LatCentroid <- function(f){
  tmp <- subset(f, x > 0)
  tmp <- subset(tmp, !is.na(y))
  if(sum(tmp$y, na.rm = TRUE) == 0){
    cent1 <- data.frame(matrix(NA, nrow = 1, ncol = 3))
    colnames(cent1) <- c("latitude", "richness", "hemisphere")
  }
  else{p <- sp::SpatialPointsDataFrame(coords = data.frame(tmp[,1:2]), data = data.frame(tmp[,3]))
  cent1 <- data.frame(spatialEco::wt.centroid(x = p, p = "tmp...3.", sp = TRUE))
  cent1 <- cbind.data.frame(cent1, c("N"))
  colnames(cent1) <- c("latitude", "richness", "hemisphere")}
  
  tmp <- subset(f, x < 0)
  tmp <- subset(tmp, !is.na(y))
  if(sum(tmp$y, na.rm = TRUE) == 0){
    cent2 <- data.frame(matrix(NA, nrow = 1, ncol = 3))
    colnames(cent2) <- c("latitude", "richness", "hemisphere")
  }
  else{p <- sp::SpatialPointsDataFrame(coords = data.frame(tmp[,1:2]), data = data.frame(tmp[,3]))
  cent2 <- data.frame(spatialEco::wt.centroid(x = p, p = "tmp...3.", sp = TRUE))
  cent2 <- cbind.data.frame(cent2, "S")
  colnames(cent2) <- c("latitude", "richness", "hemisphere")}
  
  return(rbind.data.frame(cent1, cent2))
}