- Notes re an old project “POA2006_centroids transformations 2010-08-06”
- https://alliance.anu.edu.au/access/content/group/bf77d6fc-d1e1-401c-806a-25fbe06a82d0/PostGIS%20wiki%20files/POA2006_centroid/POA2006_centroids_transformations_doc.html
- compared population weighted centroids with Geographic POA centroids
- Postal Areas (POA) are not the same as Postcodes! See this fact sheet
- But my old work gives the total areas as 695.6 square decimal degrees
- This compares with the area of Australia at 7.692 million sq kms.
- So this update uses Geoscience Australia Lambert to avoid distorting the area
- http://spatialreference.org/ref/epsg/3112/
Download
'name:poa06-area-lambert'
setwd("~/projects/POA_centroids/POA2006_centroids")
library(swishdbtools)
ch <- connect2postgres2("delphe")
fout_geo=dbGetQuery(ch,
'select poa_2006,
st_area(st_transform(the_geom, 3112))/1000000 as Geoscience_Australia_Lambert_area_km2,
st_x(st_centroid(st_transform(the_geom,3112))) as geocentx,
st_y(st_centroid(st_transform(the_geom,3112))) as geocenty
from abs_poa.auspoa06')
str(fout_geo)
sum(fout_geo$geoscience_australia_lambert_area_km2)
write.table(fout_geo,'data_derived/auspoa06_geocentroids_lambert_20160624.csv',
row.names=F, sep=',')
plot(fout_geo[,3:4])
head(fout_geo)
nrow(fout_geo)
2507
