[postgis-users] How can i get accurate world coordinate (WGS84)with mouse click?

[Curtis W. Ruck]

>From what I see your Y (latitude) scaling in your translation from screenpoint to coordinate point application isn't accounting for latitudes further away from the equator.  

Inside your application you should have something that calculates the translation for longitude properly (longitude appears fine), so replicate the scaling that you are using for your longitude for your latitude also, don't reuse the scaling variable in your latitude math from your longitude math.

Curtis

----- Original Message ----
From: Alex Chew <alex_chew at 163.com>
To: PostGIS Users Discussion <postgis-users at postgis.refractions.net>
Sent: Monday, November 27, 2006 10:39:47 PM
Subject: Re: Re: [postgis-users] How can i get accurate world coordinate (WGS84)with mouse click?





 





Hi，Markus


  　Can you read image 

followed?


All red points are mouse clicked 

point in Screen Coordinate and green points are in World 

Coordinate.


I am still got know idea 

about why this happened. 


X is accurate while Y is 

error.


 


Would you please show me the way to a 

resolution?


Thanks


Alex 　　　　　


　　　　　　　　　　　　　　　




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