[gdal-dev] TransformPoint returning Infinity

[Henneke, Amanda M]

Thanks Frank!  Don't I feel dumb now!  Although, I'm glad it was that simple! 


Amanda M. Henneke


 
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-----Original Message-----
From: Frank Warmerdam [mailto:warmerdam at pobox.com] 
Sent: Tuesday, October 20, 2009 9:36 AM
To: Henneke, Amanda M
Cc: gdal-dev at lists.osgeo.org
Subject: Re: [gdal-dev] TransformPoint returning Infinity

Henneke, Amanda M wrote:
> Hello all-
> 
> I've been running into a problem where I'm trying to transform points into UTM NAD83 and occasionally (does not seem to be repeatable, more random) the TransformPoint method returns Infinity for the x and y coordinate.  Just for your info, the coordinate system I'm converting from is UTM NAD27.  Anyone else seen this?  I've included my code below...am I doing something wrong or is there some sort of an issue with the TransformPont method?
> 
> // Get the input layer's spatial reference information 
> OSGeo.OSR.SpatialReference sr = lyrOriginal.GetSpatialRef(); string 
> sSpRefWKT = "";
> 
> // If this is a valid spatial reference, then export the data to a 
> string and return it if (Validator.IsValid_SpatialRef(sr))
> {
>         sr.ExportToPrettyWkt(out sSpRefWKT, 1); } sr.Dispose();
> 
> OSGeo.OSR.SpatialReference srOld = new 
> OSGeo.OSR.SpatialReference(sSpRefParams);
> OSGeo.OSR.SpatialReference srNew = new OSGeo.OSR.SpatialReference("");
> 
> srNew.SetUTM(11, 1);
> srNew.SetWellKnownGeogCS("NAD83");
> 
> ctTransform = new OSGeo.OSR.CoordinateTransformation(srOld, srNew);
> 
> double[] dLnSegPt1 = { dX1, dY1 };
> ctTransform.TransformPoint(dLnSegPt1);
>   

Amanda,

TransformPoint() takes a three entry array, try it with:

   double [] dLnSegPt1 = { dX1, dY1, 0.0 };
   ctTransform.TransformPoint(dLnSegPt1);

Best regards,

-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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