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Discriminant Analysis used with GPS scans

PhilipLeitch
1-Newbie

Discriminant Analysis used with GPS scans

In a previous post I outlined a GPS project I am working on.

http://collab.mathsoft.com/read?131519,15e#131519

The work has been interesting. I'm posting my "proof of concept" work that relates to identifying an unknown scan.

The logic is, we have GPS scans occurring and we want to classify the unknown scan into specific premises collection groups (these groups are then assigned to specific premises later).

When a new GPS scan occurs we can then use the current group information to classify it into one of the existing groups.

Note - a simple "confidence interval" will not work very well as some houses and larger complexes move any of their bins up or down the street, up to 20 metres or so. This gives cluster with an ellipse rather than a circle. Cluster analysis handles this quite nicely though.

The end process ends up creating some 50,000 or so clusters. The dataset is so big that Mathcad can't handle it. The precision required so high that it is beyond SQL Server. I have to use "Decimal" variable type in C# in order to process all of the data.

However I have produced a simple table of "loadings" so that identification of any new scan can be done in moments. The driver can be presented a list of "most likely" locations (premises with the highest score of the classifying function) so they can select the correct location.

Philip
___________________
Nobody can hear you scream in Euclidean space.
4 REPLIES 4

On 1/21/2010 8:35:09 PM, pleitch wrote:

>The end process ends up
>creating some 50,000 or so
>clusters. The dataset is so
>big that Mathcad can't handle
>it. The precision required so
>high that it is beyond SQL
>Server. I have to use
>"Decimal" variable type in C#
>in order to process all of the
>data.

Maybe you like XNUMBERS DLL ActiveX at

http://digilander.libero.it/foxes/SoftwareDownload.htm

Before installing the activex, can try the excel macros.

I think that this can be implemented in mathcad with vbs as component, but I never exceed usual precisions.

Regards. Alvaro.

The C# version is very quick (quicker than Mathcad), so I'm happy with that at the moment. Mathcad might run the full dataset if my memory was bigger as it is an out of memory error I get.

That's not surprising seeing as there are currently 1,103,971 individual data points (growing by 10-15,000 records per day).

But thanks for the tip.

Philip
___________________
Nobody can hear you scream in Euclidean space.

Are posting for the red or what ?



jmG

I work in Mathcad 14 (and occasionally 13) I use "Save As" to save back to 11. I cannot guarantee the 11 version will work as I have no means of loading it to check.

If parts don't work then I would suggest you use the Mathcad 14 version.

Cheers,
Philip
___________________
Nobody can hear you scream in Euclidean space.
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