How to obtain increase/decrease price change by date in sas?

[Ganeshk]

Hi,

i have a data set with 4 variable, data set is shown below:

Storeid ProdId Date SP

1 101 22/1/2013 18

1 101 23/1/2013 18

1 101 24/1/2013 19

1 101 25/1/2013 18

1 101 26/1/2013 19

1 101 27/1/2013 19

Require output is:

Storeid ProdId Date SP

1 101 22/1/2013 18

1 101 24/1/2013 19

1 101 25/1/2013 18

1 101 26/1/2013 19

How to retrieve particular record when price is increasing or decresing?

[Steelers_In_DC]

Here is a solution, one comment though.  Before checking your solution I wrote _N_ > 1 before first.date, didn't think you would want the first record.

data have;

infile cards;

informat date ddmmyy10.;

format date mmddyy10.;

input Storeid$ ProdId$ Date SP;

cards;

1 101 22/1/2013 18

1 101 23/1/2013 18

1 101 24/1/2013 19

1 101 25/1/2013 18

1 101 26/1/2013 19

1 101 27/1/2013 19

;

run;

data want;

set have;

_l_sp = lag(sp);

by date notsorted;

if first.date and _l_sp > sp then _increase = 1;

if first.date and _l_sp < sp then _decrease = 1;

if _increase = 1 or _decrease = 1 then output;

drop _:;

run;

[slchen · Accepted solution]

data want;

   set have;

   by date notsorted;

   if sp=lag(sp) then delete;

run;

[Astounding]

Another opinion:

data want;

   set have;

   by StoreID ProdID SP notsorted;

   if first.sp;

run;

Edited a couple of times, but this should do the trick.  Good luck.

[Astounding]

And so what would the right outcome be for this data?  And what do your solutions actually generate?

Storeid ProdId Date SP

1 101 22/1/2013 18

1 101 23/1/2013 18

1 101 24/1/2013 19

1 101 25/1/2013 18

1 101 26/1/2013 19

1 101 27/1/2013 19

1 102 22/1/2013 19

1 102 23/1/2013 20

1 102 24/1/2013 20

1 102 25/1/2013 21