KDB+ / Q unique random values with variable for amount

Question

I am quite new to KDB+ and have a question about generating random numbers.

Lets say I want to create num random unique numbers.

When i use this

q)10?10
q)-10?10

I get 10 random numbers in line 1 and 10 unique random numbers in line 2 (range from 0 to 9)

When I want to introduce a variable like this

q)num:10
q)num?10  / works
q)-num?10 / dont work

The generation of unique randoms does not work.

Whats the correct syntax for this?

Thanks in advance

score 2 · Accepted Answer · answered May 30 '15 at 16:32

2

This will give you num unique numbers between 0 and 9.

q)(neg num)?10

answered May 30 '15 at 16:32

coopejoh

okay, this seems to work fine for some datatypes. But what about this `q)(neg num)?2001.01.01` – Martin Mlostek May 30 '15 at 17:00
The distinct does not work with dates. `q)-10?2001.01.01 'type` try adding distinct numbers to a date if you are looking for distinct dates. – coopejoh May 30 '15 at 18:51
date is an integer under the hood. So you can convert any sane integer to a date after randomising however many you want – Manish Patel May 31 '15 at 09:49
okay, thanks very much. didnt think of using distinct number addition and casting. – Martin Mlostek May 31 '15 at 11:31

1 Answers1