• kdb+

  Running Entry Count

  Posted by Laura on April 6, 2022 at 12:00 am

  Hey Qbies,

  I have a table containing for multiple symbols that I’m looking to count rows…

  For example:

  symbol | symbol count | dataset count
  
  aapl | 1 | 1
  
  aapl| 2 | 2
  
  goog| 1 | 3 
  
  
  

  Basically, I want to get identify the row count by symbol and then by dataset. I know that I can just grab “i” to get the rowcount for the dataset, but I’m having trouble pulling a symbol count

  Thanks!

  Laura replied 8 months ago 1 Member · 2 Replies
• 2 Replies

• 

  Laura

  Administrator

  April 6, 2022 at 12:00 am

  sums i=i by sym

  did the trick

• 

  Laura

  Administrator

  April 7, 2022 at 12:00 am

  Not entirely clear what youre looking for here. If you want to produce a 1N list for each symbol you can use til and avoid the sums and comparisons:

   

  q)select 1+til count i by sym from t 
  sym | x 
  ----| --------------- 
  aapl| 1 2 3 4 5 
  goog| 1 2 3 4 5 6 7 8 
  msft| 1 2 3 4 5 6 7

   

  but its hard to see a use for the lists. Perhaps you simply want to count rows for each symbol?

  q)exec count i by sym from t 
  aapl| 5 
  goog| 8 
  msft| 7 
  
  q)ts:1000 select sums i=i by sym from t 
  4 10720 
  
  q)ts:1000 exec count i by sym from t 
  1 9584

   

   

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