R/owin.R

In qspatialR/qspatial: Areal and Point Pattern Data Visualization and Analysis

#' old version of as.owin function
#'
#' that still works
#'
as.owin2 =  function(SP) {
  # require(spatstat)
  # if (!is.na(sp::is.projected(SP)) && !sp::is.projected(SP))
 #  stop("Only projected coordinates may be converted to spatstat class objects")
 #if (!requireNamespace("spatstat", quietly = TRUE))
 #  stop("package spatstat required for .SP2owin")
  pls <- slot(SP, "polygons")
  nParts <- sapply(pls, function(x) length(slot(x, "Polygons")))
  nOwin <- sum(nParts)
  if (nOwin == 1) {
    pl <- slot(pls[[1]], "Polygons")
    crds <- slot(pl[[1]], "coords")
    colnames(crds) <- c("x", "y")
    rD <- pl[[1]]@ringDir
    if (rD == 1) crds <- crds[nrow(crds):1,]
    crds <- crds[-nrow(crds),]
    res <- spatstat::owin(poly=list(x=crds[,1], y=crds[,2]))
  } else if (nOwin > 1) {
    opls <- vector(mode="list", length=nOwin)
    io <- 1
    for (i in seq(along=pls)) {
      pl <- slot(pls[[i]], "Polygons")
      for (j in 1:nParts[i]) {
        crds <- slot(pl[[j]], "coords")
        colnames(crds) <- c("x", "y")
        rD <- slot(pl[[j]], "ringDir") # sp:::.spFindCG(crds)$rD
        hole <- slot(pl[[j]], "hole")

        if (rD == -1 && hole) crds <- crds[nrow(crds):1,]
        else if (rD == 1 && !hole) crds <- crds[nrow(crds):1,]

        crds <- crds[-nrow(crds),]

        opls[[io]] <- list(x=crds[,1], y=crds[,2])
        io <- io+1
      }
    }
    #	if (exists(".spatstat_check") && !.spatstat_check)
    if (!spatstat::spatstat.options("checkpolygons"))
      res <- spatstat::owin(bbox(SP)[1,], bbox(SP)[2,], poly = opls,
                            check=FALSE)
    # 070718 added check avoidance
    else res <- spatstat::owin(poly=opls)
  } else stop("no valid polygons")
  res
}