R/as.wmppp.ppp.R

In dbmss: Distance-Based Measures of Spatial Structures

as.wmppp.ppp <-
function(X, ...) 
{
  Marks <- marks(X)
  
  # Marks are a dataframe with colums PointType and PointWeight
  if (is.data.frame(Marks)) {
    names(Marks) <- tolower(names(Marks))
    # Read Point Weights
    if ("pointtype" %in% names(Marks)) {
      PointType <- Marks[, "pointtype"]
    }
    if (!is.factor(PointType))  {
      PointType <- as.factor(PointType)
    }    
    if ("pointweight" %in% names(Marks)) {
      PointWeight <- Marks[, "pointweight"]
    }      
    if (!is.numeric(PointWeight))  {
      stop("Point weights have been found in the marks of the point pattern but they must be numeric.")
    }    
  } else {
    # Marks are types, set types to "All"  
    if (is.factor(Marks)) {
      PointType <- Marks
    } else {
      PointType <- rep("All", X$n)
    }
    # Marks are numbers: use them as weights, else set weights to 1
    if (is.numeric(Marks)) {
      PointWeight <- Marks
    } else {
      PointWeight <- rep(1, X$n)
    }
  }
  # Check weights are positive
  if (any(PointWeight < 0)) {
    stop("Point weights must be positive.")
  }
  
  wmpppX <- X
  marks(wmpppX) <- data.frame(PointWeight, PointType)
  class(wmpppX) <- c("wmppp", "ppp")
  return (wmpppX)
}