On Fri, Nov 12, 2010 at 11:27 AM, Franziska Schulze
<franziska.schu...@wiwi.hu-berlin.de> wrote:
> Dear all,
>
> I have a SpatialPolygonsDataFrame and I want to add data to the regions, i.e.
> I want to assign to every region in my data a value of a certain variable. I
> tried using spCbind, but after using this, the dimensions of my
> SpatialPolygonsDataFrame changed. What went wrong? Do I have to create a
> matrix with the region's IDs and the values of my variable?
You can for the most part treat it like a data frame. For example,
using the spdf created in help("SpatialPolygonsDataFrame-class")
> summary(ex_1.7)
Object of class SpatialPolygonsDataFrame
Coordinates:
min max
x 0.5 10.5
y 0.5 10.5
Is projected: NA
proj4string : [NA]
Data attributes:
x y z
Min. : 1.0 Min. : 1.0 Min. :1.702
1st Qu.: 3.0 1st Qu.: 3.0 1st Qu.:2.626
Median : 5.5 Median : 5.5 Median :3.123
Mean : 5.5 Mean : 5.5 Mean :3.127
3rd Qu.: 8.0 3rd Qu.: 8.0 3rd Qu.:3.614
Max. :10.0 Max. :10.0 Max. :4.600
> ex_1.7$FOO=99
> summary(ex_1.7)
Object of class SpatialPolygonsDataFrame
Coordinates:
min max
x 0.5 10.5
y 0.5 10.5
Is projected: NA
proj4string : [NA]
Data attributes:
x y z FOO
Min. : 1.0 Min. : 1.0 Min. :1.702 Min. :99
1st Qu.: 3.0 1st Qu.: 3.0 1st Qu.:2.626 1st Qu.:99
Median : 5.5 Median : 5.5 Median :3.123 Median :99
Mean : 5.5 Mean : 5.5 Mean :3.127 Mean :99
3rd Qu.: 8.0 3rd Qu.: 8.0 3rd Qu.:3.614 3rd Qu.:99
Max. :10.0 Max. :10.0 Max. :4.600 Max. :99
>
The dimension will change because you are adding a new column - if the
number of rows have changed then something is going wrong...
Post some code?
Barry
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