[OpenLayers-Users] area enclosed by linestring

[Tobias Reinicke]

Fair enough. I presume you aren't drawing the linestring by hand yes?
and that there are no obvious rounding errors?

Toby

On 15 January 2012 21:23, Jim White <jbw2003 at earthlink.net> wrote:
> I tried that first. It was way off. I think by a factor of cos(lat)**2.
>
>
>
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> On 01/15/2012 03:24 PM, Toby Reinicke wrote:
>>
>> Do you have the same issue if you just use ring.getArea() function?
>>
>> On 15 Jan 2012, at 18:31, Jim White<jbw2003 at earthlink.net>  wrote:
>>
>>> Hi,
>>>
>>> I use this to calculate the number of acres enclosed by a linestring:
>>>
>>> ring = new OpenLayers.Geometry.LinearRing(geometry.getVertices());
>>> area = ring.getGeodesicArea(new OpenLayers.Projection("EPSG:900913"));
>>> area = Math.floor(Math.abs(area*0.000247105381));
>>>
>>> The calculated area consistently produces results that are 2-3% too
>>> small. Is this an error in my code or is my data the problem?
>>>
>>> Thanks,
>>> Jim White
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>
>