[postgis-users] am I misunderstanding distance() or a bug?

[Jessica M Salmon]

Hi.

I have a series of multipolygons, and I'm looking at the distance to a
polygon. I'm expecting the minimum distance present from any element of the
multipolygon to the polygon. The results I am getting seem to differ from
this. I am including a text file of the multipolygons. Below is the
polygon:

POLYGON((-1564405.57967217 917321.385045534,-1564415.18573468
917224.177005106,-1564443.33705241 917130.372305328,-1564489.75474523
917043.606382422,-1564551.79726961 916967.888498341,-1564627.66941105
916906.03789935,-1564714.1620692 916859.618749636,-1564807.86099769
916831.072430251,-1564905.65881979 916821.524189971,-1565002.93194515
916831.282589218,-1565096.98228938 916859.7178206,-1565183.49342054
916905.822015044,-1565258.8933726 916967.835751554,-1565321.33121997
917043.938761378,-1565367.74777771 917130.178227596,-1565395.85582122
917224.169265321,-1565405.49896118 917321.711804598,-1565395.87917988
917418.918608697,-1565367.61194391 917513.157861817,-1565321.28554385
917599.478700146,-1565259.23594921 917675.188896901,-1565183.25946987
917737.470310064,-1565096.87269694 917783.444049256,-1565003.18210399
917811.985711052,-1564905.39629291 917821.532094732,-1564808.13690193
917811.774929226,-1564714.10005184 917783.343841916,-1564627.600039
917737.246059431,-1564552.20711773 917675.239987667,-1564489.77122626
917599.14483291,-1564443.35123283 917512.912150344,-1564415.23478419
917418.925726102,-1564405.57967217 917321.385045534,-1564405.57967217
917321.385045534))

It's a nice, simple circle. I'm working in Alber's Equal Area, for which I
created my own spatial_ref_sys entry:

 102008 | ESRI      |    102008 |
PROJCS["North_America_Albers_Equal_Area_Conic",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137,298.257222101]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Albers"],PARAMETER["False_Easting",0],PARAMETER["False_Northing",0],PARAMETER["Central_Meridian",-96],PARAMETER["Standard_Parallel_1",20],PARAMETER["Standard_Parallel_2",60],PARAMETER["Latitude_Of_Origin",40],UNIT["Meter",1]]
 | +proj=aea +lat_1=20 +lat_2=60 +lat_0=40 +lon_0=-96 +x_0=0 +y_0=0
+ellps=GRS80 +datum=NAD83 +units=m

The results of select postgis_full_version();
                               postgis_full_version
----------------------------------------------------------------------------------
 POSTGIS="1.1.1" GEOS="2.2.1-CAPI-1.0.1" PROJ="Rel. 4.4.9, 29 Oct 2004"
USE_STATS
(1 row)

If someone could take a look and tell me if it looks normal to them or not,
I would be most appreciative.

(See attached file: testcase.txt)
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