Re: [R] point.in.polygon help
It would be useful to know what your ultimate goal is. On Wed, May 22, 2013 at 6:29 AM, karengrace84 kgfis...@alumni.unc.edu wrote: I am new to mapping with R, and I would like to use the point.in.polygon function from the sp package, but I am unsure of how to get my data in the correct format for the function. The generic form of the function is as follows: point.in.polygon(point.x, point.y, pol.x, pol.y, mode.checked=FALSE) I have no problem with the point.x and point.y inputs. I have a list of gps longitudes and latitudes that will go in fine. My problem is with the pol.x and pol.y input. My polygon is currently in the form of a SpatialPolygonsDataFrame created by inputting shp files with the rgdal package. How do I get a numerical array of the x- and y-coordinates from my polygon that will go into the point.in.polygon function? -- View this message in context: http://r.789695.n4.nabble.com/point-in-polygon-help-tp4667645.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. -- Daisy Englert Duursma Department of Biological Sciences Room E8C156 Macquarie University, North Ryde, NSW 2109 Australia Tel +61 2 9850 9256 __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] point.in.polygon help
I am looking at fish tagging data. I have gps coordinates of where each fish was tagged and released, and I have a map of 10 coastal basins of the state of Louisiana. I am trying to determine which basin each fish was tagged in. -- View this message in context: http://r.789695.n4.nabble.com/point-in-polygon-help-tp4667645p4667808.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] point.in.polygon help
In that case I'd definitely look more at the over() function than that ugly bit I suggested before. Get your fish info into a SpatialPointsDataFrame Since your polygons are in a SpatialPolygonsDataFrame, I would expect the data frame part has one row per basin, and it contains the basin names or other unique identifier. Loop through the basin names, subsetting the SpatialPolygonsDataFrame for each each basin, then use the over() function the with the fish SpatialPointsDataFrame to tell you which fish are in the current basin. That's an outline; there are obviously lots of details that would be needed. This should work even if, for example, a single basin consists of more than one polygon (presumably non-overlapping). There may be a more efficient way, but I don't know it off the top of my head. -Don -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 5/23/13 6:03 AM, karengrace84 kgfis...@alumni.unc.edu wrote: I am looking at fish tagging data. I have gps coordinates of where each fish was tagged and released, and I have a map of 10 coastal basins of the state of Louisiana. I am trying to determine which basin each fish was tagged in. -- View this message in context: http://r.789695.n4.nabble.com/point-in-polygon-help-tp4667645p4667808.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] point.in.polygon help
First suggestion is to ask the question on r-sig-geo. There is the over() function in the sp package, though it may require you to put your points in a spatial class object. For a crude brute-force approach that does not easily generalize, but might be the quickest short-term solution for you right now, and assuming your object has just a single polygon, try this: your.spdf@polygons[[1]]@Polygons[[1]]@coords That should give you a two column matrix representing your polygon. You may need to remove the last row for pol.x and pol.y, since in this implementation the last row = the first row. -Don -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 5/21/13 1:29 PM, karengrace84 kgfis...@alumni.unc.edu wrote: I am new to mapping with R, and I would like to use the point.in.polygon function from the sp package, but I am unsure of how to get my data in the correct format for the function. The generic form of the function is as follows: point.in.polygon(point.x, point.y, pol.x, pol.y, mode.checked=FALSE) I have no problem with the point.x and point.y inputs. I have a list of gps longitudes and latitudes that will go in fine. My problem is with the pol.x and pol.y input. My polygon is currently in the form of a SpatialPolygonsDataFrame created by inputting shp files with the rgdal package. How do I get a numerical array of the x- and y-coordinates from my polygon that will go into the point.in.polygon function? -- View this message in context: http://r.789695.n4.nabble.com/point-in-polygon-help-tp4667645.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] point.in.polygon help
I am new to mapping with R, and I would like to use the point.in.polygon function from the sp package, but I am unsure of how to get my data in the correct format for the function. The generic form of the function is as follows: point.in.polygon(point.x, point.y, pol.x, pol.y, mode.checked=FALSE) I have no problem with the point.x and point.y inputs. I have a list of gps longitudes and latitudes that will go in fine. My problem is with the pol.x and pol.y input. My polygon is currently in the form of a SpatialPolygonsDataFrame created by inputting shp files with the rgdal package. How do I get a numerical array of the x- and y-coordinates from my polygon that will go into the point.in.polygon function? -- View this message in context: http://r.789695.n4.nabble.com/point-in-polygon-help-tp4667645.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
[R] point.in.polygon help
x - sapply(c(1:max(greens[,1])), function() {
poly.x - greens[greens[,1] == hole, 2]
poly.y - greens[greens[,1] == hole, 3]
p.x - gps[,3]
p.y - gps[,4]
require(sp)
gps[which(point.in.polygon(p.x,p.y,poly.x,poly.y) != 0),ncol(gps)]
- gps[which(point.in.polygon(p.x,p.y,poly.x,poly.y) != 0),ncol(gps)]
+ 0.2
}
gps is a set of GPS readings from a golf course and greens is a
data.frame consisting of coordinates for the 18 holes. The code above
is supposed to show which (gps[,3], gps[,4]) lie within a polygon with
edges p.x, and p.y. It's not quite working, samples from gps and
greens follow:
head(greens)
holeno latitude longitude
1 1 37.55451273121 -122.3801181128
2 1 37.55446160943 -122.3801234772
3 1 37.55443003419 -122.3801140894
4 1 37.55440898403 -122.3800966551
5 1 37.55440296970 -122.3800778796
6 1 37.55438342311 -122.3800644686
head(gps)
logged_on longitude latitude speed tag_id track score
1 132173859 -122.3811569214 37.55739593506 0.14 NA 95.84 0.2
2 1321738591000 -122.3812255859 37.55743408203 0.15 NA 95.84 0.2
3 1321738592000 -122.3812179565 37.55741882324 0.27 NA 95.84 0.2
4 1321738593000 -122.3812789917 37.55744934082 0.53 NA 95.84 0.2
5 1321738594000 -122.3812789917 37.55744552612 0.11 NA 95.84 0.2
6 1321738595000 -122.3812637329 37.55744171143 0.06 NA 95.84 0.2
There should be about 36 points in the polygon outlined and the code
is outputting no points. Many thanks and do be in touch if you desire
further information...
--
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