[gdal-dev] TransformPoint returning Infinity

[Frank Warmerdam]

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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