Hi.
For a spatial analysis (its visualization) I need to produce a map of
conditions and traits.
When I used SpatialPixelsDataFrame (sp package) my grid cells were regular
and between each row was a small gap, which is not only messy but incorrect.
So I generated the coords of each grid from the centroids in order to
elongate the cells manually (or does anybody know another way to solve
this?).
But I got stuck when I tried to convert the XMIN, XMAX, YMIN, YMAX - corner
points to a list of polygons (and keeping at least the ID as individuell
reference).
I really don’t get it, how can I read data of this format as a list of
polygons?
„head"(ID, XMIN, XMAX, YMIN, YMAX, lat, lng, altc_mean)
polys <- Polygons(list(Polygon(assemblage[,c("XMIN", "XMAX", "YMIN",
"YMAX“)])), ID=assemblage$ID)
SP <- SpatialPolygons(polys)
SPDF <- SpatialPolygonsDataFrame(SP, data=data.frame(x= assemblage$lng, y=
assemblage$lat, row.names=row.names(SP)))
Already thanks for your help,
Stefan
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