[R] data transformation

[Christian Hof]

Dear all,
how can I, with R, transform a presence-absence (0/1) matrix of species 
occurrences into a presence-only table (3 columns) with the names of the 
species (1st column), the lat information of the sites (2nd column) and 
the lon information of the sites (3rd column), as given in the below 
example?
Thanks a lot for your help!
Christian


my dataframe:

site	lat	lon	spec1	spec2	spec3	spec4
site1	10	11	1	0	1	0
site2	20	21	1	1	1	0
site3	30	31	0	1	1	1


my desired new dataframe:

species	lat	lon
spec1	10	11
spec1	20	21
spec2	20	21
spec2	30	31
spec3	10	11
spec3	20	21
spec3	30	31
spec4	30	31



-- 
Christian Hof, PhD student

Center for Macroecology & Evolution
University of Copenhagen
www.macroecology.ku.dk
&
Biodiversity & Global Change Lab
Museo Nacional de Ciencias Naturales, Madrid
www.biochange-lab.eu

mobile ES .. +34 697 508 519
mobile DE .. +49 176 205 189 27
      mail .. chof at bio.ku.dk
     mail2 .. vogelwart at gmx.de
      blog .. www.vogelwart.de