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rshapefilergdal

R spCbind error

I have successfully added information to shapefiles before (see my post on http://rusergroup.swansea.ac.uk/Healthmap.ashx?HL=map ).

However, I just tried to do it again with a slightly different shapefile (new local health boards for Wales) and the code fails at spCbind with a "row names not identical error"

o <- match(wales.lonlat$NEW_LABEL, wds$HB_CD)
wds.xtra <- wds[o,]
wales.ncchd <- spCbind(wales.lonlat, wds.xtra)

My rows did have different names before and that didn't cause any problems. I relabeled the column in wds.xtra to match "NEW_LABEL" and that doesn't help.

The labels and order of labels do match exactly between wales.lonlat and wds.xtra.

(I'm using Revolution R 5.0, which is built on R 2.13.2)

Solution

  • I use match to merge data to the sp data slot based on rownames (or any other common ID). This avoids the necessity of maptools for the spCbind function. 

    # Based on rownames
sdata@data=data.frame(sdata@data, new.df[match(rownames(sdata@data), rownames(new.df)),])

# Based on common ID
sdata@data=data.frame(sdata@data, new.df[match(sdata@data$ID, new.df$ID),])

# where; sdata is your sp object and new.df is a data.frame object that you want to merge to sdata.