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What does the error in the title mean? I'm fairly new to GIS and can't understand which negative length vectors R is talking about? Here is what I'm doing:

I have a csv of lat/long locations of certain points and a multiPolygon Shapefile of buildings in a particular city . I want to find the nearest polygon to each point. First I have converted the points and polygons to planar projections by the following code:

##BUILDINGS DATA

buildings<-readOGR("buildings.shp")
buildings<- spTransform(buildings, CRS("+proj=utm +zone=45 +a=6377299.151
                                        +b=6356098.145120132 
                                        +towgs84=295,736,257,0,0,0,0 +units=m +no_defs "))

##LATITUDES/LONGITUDES DATA

locations<-read.csv("20190712033434-47083-data.csv")

locations <- SpatialPointsDataFrame(coords = locations, data = locations,
                                    proj4string = 
                                      CRS("+proj=longlat +datum=WGS84"))
locations<- spTransform(locations, CRS("+proj=utm +zone=45 +a=6377299.151
                                        +b=6356098.145120132 
                                        +towgs84=295,736,257,0,0,0,0 +units=m +no_defs "))

Then I find the minimum distance using the following formula:

minimum_distance<- apply(gDistance(locations, buildings,byid=TRUE),2,min)

But it gives me the error:

Error in RGEOSDistanceFunc(spgeom1, spgeom2, byid, "rgeos_distance") : 
  negative length vectors are not allowed

What is going wrong?

  • is it possible some of the points are inside the polygons? – Ian Turton Jul 17 at 9:12
  • Yes it is possible. – Ron Howard Jul 17 at 9:13
  • Hard for us to track down without your data, and nothing obviously wrong with the code. Subset locations and buildings and see if its down to a particular item in one or the other. – Spacedman Jul 17 at 9:43

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