# Deleting shapefile polygons that doesn't much with record in the merge dbf file
I want to do: 1. Delete polygons that doesn't have a match with record in joined / merge table of the shapefile. (Done transpose and merging - joined to one-to-one relationship already.) 2. Create a subset of the polygon and save shapefile or just save the revise shapefile 3. Open in shapefile in QGIS and do spplot. ~~~~~~~~~~~~~~ from 1 to 93 polygon if table ID == polygon_ID then print("Polygon OK") else delete the polygon How do I delete the polygon and save? ~~~~~~~~~~~~~ getwd() setwd('C:\\Down2\\R_forestmgt\\modelIII\\') library(rgdal) forest <- readOGR(".", "ForestStand") forest.dat <- slot(forest, "data") <------ is this necessary? xlength<-nrow(forest.dat) for (i in 1:xlength) if (forest.dat$ID[x] == forest[ID[x] {print("Polygon OK") } else { Delele Polygon} writeOGR(forest, ".", "ForestStandNew", "ESRI Shapefile") ~~~~~~~~~~~~~~~~~ The script above doesn't run because I don't know how to delete polygons. Any ideas how to do this? Thanks in advance. Noli _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo