[Proj] GDM2000 for Malaysia

[Bjørn Krangnes]

Hi,
TransformPoint() is a public void function (TransformPoint(double[]
inout)) and give no return value.
You were right I have mixed x and y and by using 103 and 1.8 I am getting
same result as you 888148.415 and -243199.561.
This is far from the expected result. Any idea what could be wrong ...

Regards
Bjørn


> On 5/4/07, Bjørn Krangnes <bkr at devonor.com> wrote:
>> I am trying convert GDM2000 – MRSO (Peninsular)
>> I am using C# and GDAL
>> The code look as follows
>>
>>             stat3 = input.ImportFromProj4("+proj=longlat +ellps=GRS80
>> +no_defs  <>");
>>             stat4 = output.ImportFromProj4("+proj=omerc +lat_0=4
>> +lonc=102.25 +alpha=323.0257964666666 +k=0.99984 +x_0=804671
>> +y_0=0 +ellps=GRS80 +units=m +no_defs  <>");
>>             xyz[0] = 1.827764875;
>>             xyz[1] = 103.64025987222223;
>>             xyz[2] = 10.0;
>>             OGR.CoordinateTransformation tram = new
>> OGR.CoordinateTransformation(input, output);
>>             tram.TransformPoint(xyz);
>> The result I am getting is : 0.0319005150210526
>>             xyz[0] = 0.0319005150210526;
>>             xyz[1] = 1.8088637723928358;
>>             xyz[2] = 10.0;
>>
>> The expected result is :
>>
>> Easting =   627096.132 m
>> Northing = 202122.062 m
>>
>> Anyone who knows what the problem is ?
>
> Bjorn,
>
> Do you check the return result from TransformPoint().  My guess would
> be that the code is giving up at some point in the transformtion in which
> case it should be returning an error code. Possibly it fails just after
> converting the values in degrees to radians?
>
> I tried something close to this with cs2cs before realizing that the
> core error is that you are presumably mixing up x and y.  The
> xyz[0] should be x or longitude, and xyz[1] should y or latitude.
> A latitude of 103 is out of bounds (-90 to 90) so the transformation
> terminates.  Unfortunately, when I switch things, I don't get a value
> very close to what you are expecting though at least it does produce
> a value.
>
> warmerda at iBook% cs2cs +proj=longlat +ellps=GRS80 +to +proj=omerc
> +lat_0=4 +lonc=102.25 +alpha=323.02579 +k=0.99984 +x_0=804671
> +ellps=GRS80
> 1.8 103
> *       * 0.00
> 103 1.8
> 888148.42       -243199.56 0.00
>
> Perhaps this helps a little?
>
> Best regards,
> --
> ---------------------------------------+--------------------------------------
> I set the clouds in motion - turn up   | Frank Warmerdam,
> warmerdam at pobox.com
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>
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Bjørn Krangnes
Devonor AS
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E-mail: bkr at devonor.com
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