topic Projecting single point in arcpy in Python Questions

Projecting single point in arcpy

DonMorrison1 — Thu, 27 Jan 2022 21:18:03 GMT

I have a script that takes in lot, long values (in decimal degrees) and determines whether the points are contained within a polygon in another feature class. I assume I have to create a point object and get it into the same coordinate system as the polygon, but the projection comes back empty (no points). I don't fully understand all the ins and outs of projections so hopefully I'm doing something obviously incorrect here.

x = -88.155675 y = 43.223869 f_cs = 'WGS 1984 Web Mercator (auxiliary sphere)' t_cs = 'NAD 1983 UTM Zone 16N' xform = 'WGS_1984_(ITRF00)_To_NAD_1983' pt = arcpy.Point(x,y) pg = arcpy.PointGeometry(pt, arcpy.SpatialReference(f_cs)) pgp = pg.projectAs(t_cs, xform) print (pgp.firstPoint)

Re: Projecting single point in arcpy

DanPatterson — Thu, 27 Jan 2022 22:24:21 GMT

you x, y aren't in web mercator,

x = -88.155675 y = 43.223869 sr = arcpy.SpatialReference(4326) t_cs = 'NAD 1983 UTM Zone 16N' xform = 'WGS_1984_(ITRF00)_To_NAD_1983' pt = arcpy.Point(x,y) pg = arcpy.PointGeometry(pt, sr) srto = arcpy.SpatialReference('NAD 1983 UTM Zone 16N') pgp = pg.projectAs(srto, xform) pgp.firstPoint <Point (406145.6122366393, 4786322.940660958, #, #)> pt <Point (-88.155675, 43.223869, #, #)>

seems to work

Re: Projecting single point in arcpy

DonMorrison1 — Thu, 27 Jan 2022 23:02:56 GMT

That's it! I must have tried a hundred combinations and at some point I was using 4326 but must have had something else off at that point. Thanks Dan!