I'm using sp::overlay between a SpPolDF and a SpPointsDF: > delme <- overlay(rndp,q1km, fn = mean) > class(q1km) [1] "SpatialPolygonsDataFrame" attr(,"package") [1] "sp" > class(rndp) [1] "SpatialPointsDataFrame" attr(,"package") [1] "sp" > class(delme) [1] "data.frame"
but I'm confused by the fact that the row.names(delme) are not the same as the row.names(q1km): > delme[1:10,] ID id val X1 356.3333 357.3333 643.3162 X2 454.3333 455.3333 653.1833 X3 305.0000 306.0000 101.8930 X4 486.7143 487.7143 448.4612 X5 456.2500 457.2500 544.1646 X6 255.4000 256.4000 139.7507 X7 403.6667 404.6667 659.8114 X8 462.5000 463.5000 537.7209 X9 629.2000 630.2000 399.1040 X10 416.5000 417.5000 278.2879 > q1km@data[1:10,] idname ID XMIN XMAX YMIN YMAX X0 X0 0 -8.994 -8.594 43.595 43.995 X1 X1 1 -8.594 -8.194 43.595 43.995 X2 X2 2 -8.194 -7.794 43.595 43.995 X3 X3 3 -7.794 -7.394 43.595 43.995 X4 X4 4 -7.394 -6.994 43.595 43.995 X5 X5 5 -6.994 -6.594 43.595 43.995 X6 X6 6 -6.594 -6.194 43.595 43.995 X7 X7 7 -6.194 -5.794 43.595 43.995 X8 X8 8 -5.794 -5.394 43.595 43.995 X9 X9 9 -5.394 -4.994 43.595 43.995 Is this the way it has to be? If it is, then it's kind of inconvenient as I would like to join the new table "delme" to q1km@data. It seems I just have to subtract 1 to the numeric part of row.names(delme), but would like to make sure. Agus _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo