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ScotchCat
Obsidian | Level 7

Be gentle, I'm new to SAS.  I need to find the File_Date each time the Product changed.  Thanks for assisting! 

Data have: 

File_date Product
12/1/2023 car
12/2/2023 car
12/3/2023 car
12/4/2023 car
12/5/2023 car
12/6/2023 truck
12/7/2023 truck
12/8/2023 truck
12/9/2023 truck
12/10/2023 truck
12/11/2023 bike
12/12/2023 bike
12/13/2023 bike

 

Data I'd like to have: 

File_date Product
12/1/2023 car
12/6/2023 truck
12/11/2023 bike
2 REPLIES 2
PaigeMiller
Diamond | Level 26
data want;
    set have;
    prev_product=lag(product);
    if product^=prev_product then output;
    drop prev_product;
run;
--
Paige Miller
ballardw
Super User

Assuming your data is grouped by the product and has the file date in sequence:

 

data want;
   set have;
   by product notsorted;
   if first.product;
run;

When you use BY in a data step SAS provides automatic variables First and Last to indicate if the observation is the first or last of the group. The Notsorted allows use of data that is grouped but not actually sorted by the BY variables.

 

 

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