topic Adjusting properties on the SpatialReference class in Python Questions

Adjusting properties on the SpatialReference class

BKuiper — Fri, 06 Apr 2012 12:57:55 GMT

Hi

I'm trying to adjust the SpatialReference using the SpatialReference class, but it doesn't seem to be working. In my example i'm trying to adjust the centralMeridian, but the final output still has the original value of -96.0.

Anybody has an idea how to make this work ?

Here is my example:

#!/usr/bin/env python

import arcpy, sys

Output_Spatial_Reference = "PROJCS['North_America_Lambert_Conformal_Conic',GEOGCS['GCS_North_American_1983',DATUM['D_North_American_1983',SPHEROID['GRS_1980',6378137.0,298.257222101]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]],PROJECTION['Lambert_Conformal_Conic'],PARAMETER['False_Easting',0.0],PARAMETER['False_Northing',0.0],PARAMETER['Central_Meridian',-96.0],PARAMETER['Standard_Parallel_1',20.0],PARAMETER['Standard_Parallel_2',60.0],PARAMETER['Latitude_Of_Origin',40.0],UNIT['Meter',1.0]];-35214300 -28218500 10000;-100000 10000;-100000 10000;0.001;0.001;0.001;IsHighPrecision"

sr = arcpy.SpatialReference()
sr.loadFromString(Output_Spatial_Reference)
sr.centralMeridian = 10.0
result = sr.exportToString()

print "printing result:"
print result

Re: Adjusting properties on the SpatialReference class

markdenil — Fri, 06 Apr 2012 14:25:48 GMT

have you tried
sr.centralMeridianInDegrees = 10.0
?

Re: Adjusting properties on the SpatialReference class

BKuiper — Sat, 11 Dec 2021 22:19:43 GMT

have you tried
sr.centralMeridianInDegrees = 10.0
?

Good idea, but that doesn't work as well.

I tried two different approaches, but it doesn't seem to work. Anybody has some ideas on what is going wrong?

here is my updated script

#!/usr/bin/env python

import arcpy, sys

# using existing string
Output_Spatial_Reference = "PROJCS['North_America_Lambert_Conformal_Conic',GEOGCS['GCS_North_American_1983',DATUM['D_North_American_1983',SPHEROID['GRS_1980',6378137.0,298.257222101]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]],PROJECTION['Lambert_Conformal_Conic'],PARAMETER['False_Easting',0.0],PARAMETER['False_Northing',0.0],PARAMETER['Central_Meridian',-96.0],PARAMETER['Standard_Parallel_1',20.0],PARAMETER['Standard_Parallel_2',60.0],PARAMETER['Latitude_Of_Origin',40.0],UNIT['Meter',1.0]];-35214300 -28218500 10000;-100000 10000;-100000 10000;0.001;0.001;0.001;IsHighPrecision"

sr = arcpy.SpatialReference()
sr.loadFromString(Output_Spatial_Reference)
sr.centralMeridian = -10.0
sr.centralMeridianInDegrees = -10.0
result = sr.exportToString()

print "printing result:"
print result

# using factory code

sr = arcpy.SpatialReference()
sr.factoryCode = 102009
sr.centralMeridian = -10.0
sr.centralMeridianInDegrees = -10.0
sr.create()

result = sr.exportToString()

print "printing result:"
print result

btw: i'm using Desktop 10.1 Prerelease, ArcObjects SDK .NET 10.1 Prerelease and ArcGIS Runtime BETA 2.

Re: Adjusting properties on the SpatialReference class

BKuiper — Mon, 09 Apr 2012 12:30:36 GMT

It seems that another user had the same problem in 2007, but no solution is given

http://forums.esri.com/Thread.asp?c=93&f=984&t=231893

Re: Adjusting properties on the SpatialReference class

BKuiper — Mon, 09 Apr 2012 12:39:48 GMT

Found another post. This might exactly explain it:
http://forums.arcgis.com/threads/32731-Modify-Spatial-Reference-Object

parameters are documented as read/write but are exactly only read. I guess the arcpy team should update the documentation or help me provide a working example.

Re: Adjusting properties on the SpatialReference class

BKuiper — Tue, 10 Apr 2012 15:59:23 GMT

So can anybody from the arcpy team confirm my findings?

It seems that these settings are only read-only, although they are marked read/write in the documentation.

It would be really helpful if these settings where actually read/write.

Thank you.

Re: Adjusting properties on the SpatialReference class

MarcHunter1 — Thu, 04 Apr 2019 22:12:24 GMT

How has such an old problem persisted to Arc Pro documentation? Can anyone from Esri answer this?