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Clustering

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Occasional Contributor
Posts: 15

Clustering

I have the following data

 

 

PS      Lat            Long         SLOT

abc    75.8233    26.2454     1
abc    75.4785    26.4589     1

abc    75.5495    26.4679     1
abc    75.4875    26.8997     2
abc    75.5649    26.7268     2
abc    75.5666    26.8647     2
xyz    75.4875    26.3842      1
xyz    75.4937    26.5877      1
xyz    75.8473    26.3971      1
xyz    75.7861    26.6884       2

 

 

Now I want a new column which shows the distances in the following way:

All the points with PS=abc and Slot=1  should have their distances calculated from the first point of this group(i.e.,  75.8233    26.2454), similarly all the points with PS=abc and Slot=2 should have their distances calculated from the first point of this group(i.e., 75.4875    26.8997) and so on.

So please suggest me a solution for this.

PROC Star
Posts: 733

Re: Clustering

Posted in reply to Himanshu007
Occasional Contributor
Posts: 15

Re: Clustering

But this function is only there for finding the distances my concern is how to fix one point from each group(group means same PS and same Slot) as a fixed reference point from which the other distances are to be found
Super User
Posts: 11,343

Re: Clustering

Posted in reply to Himanshu007

Assuming your data are sorted by PS and Slot as implied by the example:

 

data want;
   set have;
   by ps slot;
   retain firstLat Firstlong;
   if first.slot then do;
      firstlat=lat;
      firstlong=long;
   end;
   Dist = geodist(firstlat,firstlong,lat,long);
   drop firstlat firstlong;
run;
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