r - SpatialPolygonsDataFrame R中每个多边形的边界框

Question

如何获取 polys 中每个多边形的 bbox？

pp <- cbind(coordinates(polys),as.data.frame(polys))  

只给我 lonlat，但我想为每个多边形获取 lat1lat2 和 lon1lon2。

polys=new("SpatialPolygonsDataFrame"
        , data = structure(list(NAMRB_EN = structure(c(6L, 45L, 2L, 41L, 31L, 
    3L, 40L, 14L, 42L, 7L, 26L, 12L, 38L, 25L, 36L, 9L, 39L, 27L, 
    32L, 19L, 43L, 21L, 15L, 22L, 20L, 9L, 17L, 11L, 33L, 44L, 37L, 
    13L, 8L, 5L, 18L, 30L, 16L, 10L, 1L, 29L, 34L, 23L, 24L, 28L, 
    4L, 35L), .Label = c("Albany", "Arctic Ocean Seaboard", "Arnaud", 
    "Atlantic Ocean Seaboard", "Attawapiskat", "Back", "Baleine", 
    "Broadback", "Churchill", "Columbia", "Eastmain", "Feuilles", 
    "Fraser", "George", "Grande Baleine", "Harricanaw", "Hayes", 
    "Hudson Bay Seaboard", "Koksoak", "La Grande", "Little Mecatina", 
    "Mackenzie", "Mississippi", "Moose", "Naskaupi", "Nass", "Natashquan", 
    "Nelson", "Nottaway", "Pacific Ocean Seaboard", "Povungnituk", 
    "Romaine", "Rupert", "Saint John", "Saint Lawrence", "Seal", 
    "Severn", "Skeena", "St.-Augustin", "Stikine", "Taku", "Thelon", 
    "Wannock", "Winisk", "Yukon"), class = "factor"), NAODA_EN = structure(c(1L, 
    5L, 1L, 5L, 4L, 4L, 5L, 4L, 4L, 4L, 5L, 4L, 5L, 2L, 4L, 2L, 2L, 
    2L, 2L, 4L, 5L, 2L, 4L, 1L, 4L, 4L, 4L, 4L, 4L, 4L, 4L, 5L, 4L, 
    4L, 4L, 5L, 4L, 5L, 4L, 4L, 2L, 3L, 4L, 4L, 2L, 2L), .Label = c("Arctic Ocean", 
    "Atlantic Ocean", "Gulf of Mexico", "Hudson Bay", "Pacific Ocean"
    ), class = "factor"), NAMRB_FR = structure(c(4L, 45L, 19L, 41L, 
    31L, 2L, 40L, 12L, 42L, 5L, 27L, 10L, 38L, 26L, 36L, 7L, 39L, 
    28L, 32L, 16L, 43L, 18L, 13L, 23L, 17L, 7L, 15L, 9L, 33L, 44L, 
    37L, 11L, 6L, 3L, 22L, 21L, 14L, 8L, 1L, 30L, 34L, 24L, 25L, 
    29L, 20L, 35L), .Label = c("Albany", "Arnaud", "Attawapiskat", 
    "Back", "Baleine", "Broadback", "Churchill", "Columbia", "Eastmain", 
    "Feuilles", "Fraser", "George", "Grande Baleine", "Harricanaw", 
    "Hayes", "Koksoak", "La Grande", "Little Mecatina", "Littoral de l'océan Arctique", 
    "Littoral de l'océan Atlantique", "Littoral de l'océan Pacifique", 
    "Littoral de la Baie d'Hudson", "Mackenzie", "Mississippi", "Moose", 
    "Naskaupi", "Nass", "Natashquan", "Nelson", "Nottaway", "Povungnituk", 
    "Romaine", "Rupert", "Saint-Jean", "Saint-Laurent", "Seal", "Severn", 
    "Skeena", "St.-Augustin", "Stikine", "Taku", "Thelon", "Wannock", 
    "Winisk", "Yukon"), class = "factor"), NAODA_FR = structure(c(3L, 
    5L, 3L, 5L, 1L, 1L, 5L, 1L, 1L, 1L, 5L, 1L, 5L, 4L, 1L, 4L, 4L, 
    4L, 4L, 1L, 5L, 4L, 1L, 3L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 5L, 1L, 
    1L, 1L, 5L, 1L, 5L, 1L, 1L, 4L, 2L, 1L, 1L, 4L, 4L), .Label = c("Baie d'Hudson", 
    "Golfe de Mexique", "Océan Arctique", "Océan Atlantique", "Océan Pacifique"
    ), class = "factor")), .Names = c("NAMRB_EN", "NAODA_EN", "NAMRB_FR", 
    "NAODA_FR"), row.names = 0:45, class = "data.frame")
        , polygons = list(<S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>, 
        <S4 object of class structure("Polygons", package = "sp")>)
        , plotOrder = c(3L, 24L, 35L, 46L, 44L, 2L, 42L, 38L, 45L, 36L, 26L, 9L, 32L, 
    1L, 20L, 39L, 27L, 31L, 43L, 25L, 16L, 7L, 30L, 40L, 6L, 15L, 
    34L, 13L, 12L, 41L, 28L, 8L, 23L, 29L, 5L, 10L, 37L, 11L, 14L, 
    33L, 4L, 22L, 18L, 19L, 17L, 21L)
        , bbox = structure(c(-152.812332679775, 40.3769750107632, -52.6362915039062, 
    83.1106262207029), .Dim = c(2L, 2L), .Dimnames = list(c("x", 
    "y"), c("min", "max")))
        , proj4string = new("CRS"
        , projargs = "+proj=longlat +datum=NAD83 +no_defs +ellps=GRS80 +towgs84=0,0,0"
    )
    )

Answer 1

空间多边形数据框有几个槽。 @data 是数据框，@polygons 是多边形。你可以先试试 str(polys@polygons) 看看你得到了什么。如果它是一个多边形列表，那么 lapply 它与 sp::bbox 函数

require(sp)
lapply(polys@polygons, bbox)