Greetings:
I would like to kindly ask for a little help. The rough code is:
#________________________________________________________
dat=data.frame(read.delim(file="all.txt", header = TRUE, sep =
"\t",
quote="\"", dec=".",na.strings = "NA"))
nc=read.shape("astae.shp", dbf.data=TRUE, verbose=TRUE)
mappolys=Map2poly(nc)
submap <- subset(mappolys, nc$att.data$NAME!="Honolulu, HI")
nc$att.data=subset(nc$att.data, nc$att.data$NAME!="Honolulu, HI")
nc$att.data[,1]=as.numeric(paste(nc$att.data$MSACMSA))
#attributes(nc$att.data)
nc$att.data=merge(nc$att.data, dat, by.x="AREA", by.y="cod",
all.x=TRUE,
sort=FALSE)
#attributes(nc$att.data)
tmp=file("tmp")
write.polylistShape(submap, nc$att.data, "tmp")
#_________________________________________________________
All works fine, but merge() changes the rownames and the link between the
polygons and the corresponding rows is lost. I tried numerous other
solutions (such as to "paste" back the old rownames), to no avail.
After a
few days, here I am. Please, if you have a moment, send a tip.
Thanks,
mihai
--
Mihai Nica
170 East Griffith Street G5
Jackson, MS 39201
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On Sat, 7 Oct 2006, Mihai Nica wrote:> Greetings: > > I would like to kindly ask for a little help. The rough code is: >Maybe R-sig-geo would be a more relevant list. Comments inline.> #________________________________________________________ > > dat=data.frame(read.delim(file="all.txt", header = TRUE, sep = "\t", > quote="\"", dec=".",na.strings = "NA"))We do not know if dat is in the same order as the shapefile. If dat$cod is malformed wrt. nc$att.data$AREA (very strange choice, in ESRI generated files often the polygon area), you are asking for trouble.> > nc=read.shape("astae.shp", dbf.data=TRUE, verbose=TRUE) > > mappolys=Map2poly(nc) > > submap <- subset(mappolys, nc$att.data$NAME!="Honolulu, HI") > > nc$att.data=subset(nc$att.data, nc$att.data$NAME!="Honolulu, HI") >In situations like this, overwriting the input is not advisable, bercause you destroy your ability to check that the output corresponds to your intentions.> nc$att.data[,1]=as.numeric(paste(nc$att.data$MSACMSA)) > > #attributes(nc$att.data) > > nc$att.data=merge(nc$att.data, dat, by.x="AREA", by.y="cod", all.x=TRUE, > sort=FALSE)Ditto.> > #attributes(nc$att.data) > > tmp=file("tmp") > > write.polylistShape(submap, nc$att.data, "tmp") >Any good reason for not using the sp class framework? The objects you are using here are very low-level and messy. library(maptools) nc_1 <- readShapePoly(system.file("shapes/sids.shp", package="maptools")[1], ID="FIPS") # put shapefile in SpatialPolygonsDataFrame nc_2 <- nc_1[coordinates(nc_1)[,1] < -80,] # subset with "[" method row.names(as(nc_2, "data.frame")) as.character(nc_2$FIPS) tmpfl <- paste(tempfile(), "dbf", sep=".") download.file("http://spatial.nhh.no/misc/nc_xtra.dbf", tmpfl, mode="wb") nc.df <- read.dbf(tmpfl) # extra data keyed on CNTY_ID nc_2$CNTY_ID nc.df$CNTY_ID nc_df2 <- merge(as(nc_2, "data.frame"), nc.df, by="CNTY_ID", sort=FALSE) all.equal(nc_df2$CNTY_ID, nc_2$CNTY_ID) row.names(nc_df2) <- nc_df2$FIPS # re-instate IDs nc_3 <- SpatialPolygonsDataFrame(as(nc_2, "SpatialPolygons"), data=nc_df2) # (if data row names do not match polygon IDs, will reorder, or fail if # any differ or absent writePolyShape(nc_3, "nc_3") This still isn't as tidy as it could be, but gives much more control than the original old-style classes. Roger> #_________________________________________________________ > > All works fine, but merge() changes the rownames and the link between the > polygons and the corresponding rows is lost. I tried numerous other > solutions (such as to "paste" back the old rownames), to no avail. After a > few days, here I am. Please, if you have a moment, send a tip. > > Thanks, > > mihai > > >-- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand at nhh.no
The answer to all your questions is simple. By the time I get a little grasp on things, they become "deprecated" :-). But my programming skills are so low, that I find this normal. My problem comes from the last two #comment lines : #(if data row names do not match polygon IDs, will reorder, or fail if # any differ or absent The two data row names differ and some are absent, that's why I used "merge" (and posted on this list, not on r-sig-geo :-)). How else can I intersect the two data.frames? Thanks so much for your help! ----- Original Message ---- From: Roger Bivand <Roger.Bivand@nhh.no> To: Mihai Nica <mihai.p.nica@gmail.com> Cc: r-help@stat.math.ethz.ch Sent: Sunday, October 8, 2006 3:10:16 PM Subject: Re: [R] merge and polylist On Sat, 7 Oct 2006, Mihai Nica wrote:> Greetings: > > I would like to kindly ask for a little help. The rough code is: >Maybe R-sig-geo would be a more relevant list. Comments inline.> #________________________________________________________ > > dat=data.frame(read.delim(file="all.txt", header = TRUE, sep = "\t", > quote="\"", dec=".",na.strings = "NA"))We do not know if dat is in the same order as the shapefile. If dat$cod is malformed wrt. nc$att.data$AREA (very strange choice, in ESRI generated files often the polygon area), you are asking for trouble.> > nc=read.shape("astae.shp", dbf.data=TRUE, verbose=TRUE) > > mappolys=Map2poly(nc) > > submap <- subset(mappolys, nc$att.data$NAME!="Honolulu, HI") > > nc$att.data=subset(nc$att.data, nc$att.data$NAME!="Honolulu, HI") >In situations like this, overwriting the input is not advisable, bercause you destroy your ability to check that the output corresponds to your intentions.> nc$att.data[,1]=as.numeric(paste(nc$att.data$MSACMSA)) > > #attributes(nc$att.data) > > nc$att.data=merge(nc$att.data, dat, by.x="AREA", by.y="cod", all.x=TRUE, > sort=FALSE)Ditto.> > #attributes(nc$att.data) > > tmp=file("tmp") > > write.polylistShape(submap, nc$att.data, "tmp") >Any good reason for not using the sp class framework? The objects you are using here are very low-level and messy. library(maptools) nc_1 <- readShapePoly(system.file("shapes/sids.shp", package="maptools")[1], ID="FIPS") # put shapefile in SpatialPolygonsDataFrame nc_2 <- nc_1[coordinates(nc_1)[,1] < -80,] # subset with "[" method row.names(as(nc_2, "data.frame")) as.character(nc_2$FIPS) tmpfl <- paste(tempfile(), "dbf", sep=".") download.file("http://spatial.nhh.no/misc/nc_xtra.dbf";, tmpfl, mode="wb") nc.df <- read.dbf(tmpfl) # extra data keyed on CNTY_ID nc_2$CNTY_ID nc.df$CNTY_ID nc_df2 <- merge(as(nc_2, "data.frame"), nc.df, by="CNTY_ID", sort=FALSE) all.equal(nc_df2$CNTY_ID, nc_2$CNTY_ID) row.names(nc_df2) <- nc_df2$FIPS # re-instate IDs nc_3 <- SpatialPolygonsDataFrame(as(nc_2, "SpatialPolygons"), data=nc_df2) # (if data row names do not match polygon IDs, will reorder, or fail if # any differ or absent writePolyShape(nc_3, "nc_3") This still isn't as tidy as it could be, but gives much more control than the original old-style classes. Roger> #_________________________________________________________ > > All works fine, but merge() changes the rownames and the link between the > polygons and the corresponding rows is lost. I tried numerous other > solutions (such as to "paste" back the old rownames), to no avail. After a > few days, here I am. Please, if you have a moment, send a tip. > > Thanks, > > mihai > > >-- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand@nhh.no ______________________________________________ R-help@stat.math.ethz.ch 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. [[alternative HTML version deleted]]
Thanks! I believe I have all I need to solve my issue. Thank you very, very much, mihai ----- Original Message ---- From: Roger Bivand <Roger.Bivand@nhh.no> To: Mihai Nica <mihainica@yahoo.com> Cc: Mihai Nica <mihai.p.nica@gmail.com>; r-help@stat.math.ethz.ch Sent: Monday, October 9, 2006 9:20:36 AM Subject: Re: [R] merge and polylist On Mon, 9 Oct 2006, Mihai Nica wrote:> The answer to all your questions is simple. By the time I get a little > grasp on things, they become "deprecated" :-). But my programming skills > are so low, that I find this normal.> My problem comes from the last two #comment lines :> #(if data row names do not match polygon IDs, will reorder, or fail if > # any differ or absent> The two data row names differ and some are absent, that's why I used > "merge" (and posted on this list, not on r-sig-geo :-)). How else can I > intersect the two data.frames?Yes, use merge, but do look carefully at both of the input data frames, the by.x= and by.y= columns, and the output data frame. The sp classes give an ID to each polygon: sapply(slot(object, "polygons"), function(x) slot(x, "ID")) and that has to be identical to the row names of the output data frame - but can be in a different order. Constructing the SpatialPolygonsDataFrame will put the data frame rows in the order of the polygons. Roger> Thanks so much for your help!----- Original Message ---- From: Roger Bivand <Roger.Bivand@nhh.no> To: Mihai Nica <mihai.p.nica@gmail.com> Cc: r-help@stat.math.ethz.ch Sent: Sunday, October 8, 2006 3:10:16 PM Subject: Re: [R] merge and polylist On Sat, 7 Oct 2006, Mihai Nica wrote:> Greetings: > > I would like to kindly ask for a little help. The rough code is: >Maybe R-sig-geo would be a more relevant list. Comments inline.> #________________________________________________________ > > dat=data.frame(read.delim(file="all.txt", header = TRUE, sep = "\t", > quote="\"", dec=".",na.strings = "NA"))We do not know if dat is in the same order as the shapefile. If dat$cod is malformed wrt. nc$att.data$AREA (very strange choice, in ESRI generated files often the polygon area), you are asking for trouble.> > nc=read.shape("astae.shp", dbf.data=TRUE, verbose=TRUE) > > mappolys=Map2poly(nc) > > submap <- subset(mappolys, nc$att.data$NAME!="Honolulu, HI") > > nc$att.data=subset(nc$att.data, nc$att.data$NAME!="Honolulu, HI") >In situations like this, overwriting the input is not advisable, bercause you destroy your ability to check that the output corresponds to your intentions.> nc$att.data[,1]=as.numeric(paste(nc$att.data$MSACMSA)) > > #attributes(nc$att.data) > > nc$att.data=merge(nc$att.data, dat, by.x="AREA", by.y="cod", all.x=TRUE, > sort=FALSE)Ditto.> > #attributes(nc$att.data) > > tmp=file("tmp") > > write.polylistShape(submap, nc$att.data, "tmp") >Any good reason for not using the sp class framework? The objects you are using here are very low-level and messy. library(maptools) nc_1 <- readShapePoly(system.file("shapes/sids.shp", package="maptools")[1], ID="FIPS") # put shapefile in SpatialPolygonsDataFrame nc_2 <- nc_1[coordinates(nc_1)[,1] < -80,] # subset with "[" method row.names(as(nc_2, "data.frame")) as.character(nc_2$FIPS) tmpfl <- paste(tempfile(), "dbf", sep=".") download.file("http://spatial.nhh.no/misc/nc_xtra.dbf";;, tmpfl, mode="wb") nc.df <- read.dbf(tmpfl) # extra data keyed on CNTY_ID nc_2$CNTY_ID nc.df$CNTY_ID nc_df2 <- merge(as(nc_2, "data.frame"), nc.df, by="CNTY_ID", sort=FALSE) all.equal(nc_df2$CNTY_ID, nc_2$CNTY_ID) row.names(nc_df2) <- nc_df2$FIPS # re-instate IDs nc_3 <- SpatialPolygonsDataFrame(as(nc_2, "SpatialPolygons"), data=nc_df2) # (if data row names do not match polygon IDs, will reorder, or fail if # any differ or absent writePolyShape(nc_3, "nc_3") This still isn't as tidy as it could be, but gives much more control than the original old-style classes. Roger> #_________________________________________________________ > > All works fine, but merge() changes the rownames and the link between the > polygons and the corresponding rows is lost. I tried numerous other > solutions (such as to "paste" back the old rownames), to no avail. After a > few days, here I am. Please, if you have a moment, send a tip. > > Thanks, > > mihai > > >-- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand@nhh.no ______________________________________________ R-help@stat.math.ethz.ch 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. -- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand@nhh.no [[alternative HTML version deleted]]