Base SAS Programming

[Himanshu007]

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

....     .............     .............     ..

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.

Also the points should not be entered manually, a programmable solution is needed.

[Himanshu007]

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

....     .............     .............     ..

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.

Also the points should not be entered manually, a programmable solution is needed.

[RW9 · Accepted solution]

Post test data in the form of a datastep, we are not here to type test data in nor guess what the structure is.  Hence this code is just a guess, also the output is a guess as you have not shown what you want out.

data first;
  set have;
  by ps slot;
  if first.slot then output;
run;
data want;
  merge have first (rename=(lat=comp_lat long=comp_long));
  by ps slot;
  dist=lat - comp_lat;
  dist2=long - comp_long;
run;

[Himanshu007]

Thnx a lot, it's exactly what I wanted.

[Ksharp]

You owe me one hundred dollars .

data have;
input PS   $   Lat            Long         SLOT;
cards;
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
;
run;

data first rest;
 set have;
 by ps slot;
 if first.slot then output first;
  else output rest;
run;
proc sql;
select b.*,1000*geodist(a.lat,a.long,b.lat,b.long,'k') as distance_in_meters
 from first as a,rest as b 
  where a.ps=b.ps and a.slot=b.slot ;
quit;