kdb+ and q

kdb+ and q

Q+A on all things kdb+ database and the q language

Forum Posts

Sorted by:

Start a conversation

.u.init in tick/u.q

I don't understand how .u.init function works in tick/u.q. Can someone explain how it works ? What is w ? I thought x y and z would be implicit function arguments ? Are there 2 functions declared on line 6 ? The two functions are del and .z.pc ? If t...

nulls from mdev

When using mdev, I was producing a number of unexpected nulls. It seemsthat the definition is based on sqrt(avg(x^2) - avg(x)) without checkingthat the difference is non-negative before taking the square root.Example:q)5 mdev 10#1e-30 0 0 0 0 0 0 0 0...

Resetting Sums

Hi All,I have a tableminute cnt 14:00 3 14:01 5 14:02 3 14:03 7 14:04 8 14:05 3 14:06 6 14:07 6 14:08 1 14:09 2 14:10 3 and I'd like to add a running count by certain intervals. ie.minute cnt 5min14:00 3 314:01 5 814:02 3 1114:03 7 1814:04 8 2614:05 ...

fill up the null value using the previous value by grouping

so I have a table date, sym, val where unfortunately, the 3rd entry sometimes is null. In that case, I want the previous value filling it up. I understood I could use "fills". But I wonder why below doesn;t work? table: update val: prev val by sym fr...

Type error from .Q.chk

Hi allThere is a HDB folder that throw "type" error if I run .Q.chk, but that HDB folder look correct to me, I can start a HDB process there and run query without problem.Just wonder how can I check more about what going wrong?Regards,

Top Kudoed Authors

User

Count

10

7

5

3

2

Main Office Contacts

Useful Information

Resources

Popular Links

Follow Us

youtube

instagram

KX. All Rights Reserved.

KX and kdb+ are registered trademarks of KX Systems, Inc., a subsidiary of FD Technologies plc.

Export Statement

Processing Notice