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leonbaum2

Hello,Is there a way to cleanly do infinite tail calls with multipleparameters?I quickly bump into the stack limit:q)f:{f x+1}q)f 0'stack@{f x+1}2001Thanks,Leon

leonbaum2

Say I have a table with three boolean flags (a,b,c) and a numericalvalue (d). I want to calculate the average value of d for allpossible filtrations of a,b,c.For example:a, b, c (all true)a, b, c in 01b (a and b true, don't filter on c)a in 01b, b in...

leonbaum2

It's quite possible I'm missing something stupid, but shouldn't the 2ndexpression work?q){x,y}[0b;1b]01bq){select from ([]a:0101b;b:0011b) where a=x,b=y}[0b;1b]'rankq){select from ([]a:0101b;b:0011b) where a=x,b=1b}[0b]a b---0 1

leonbaum2

Is there a way to subset a dictionary without having to reconstruct it?In the example below, the last output is what I want:q)d:til[5]!5#.Q.aq)d0| a1| b2| c3| d4| eq)d where 2

leonbaum2

Hello,So I was surprised by these results:q)null ([] x:0 1 2) lj ([x:3 4 5] y:til 3;z:010b)x y z-----0 1 00 1 00 1 0q)"b"$0n1bAfter checking the reference docs, I see that the boolean datatype hasno null value. Was this design decision made because o...

leonbaum2

On 29 July 2014 15:23 UTC, Charles Skelton wrote:> maybe iterate and converge can help you> http://code.kx.com/wiki/Reference/BackSlash#iterate> http://code.kx.com/wiki/Reference/Slash>Thanks, Charles. The monadic over with an always true while condi...

leonbaum2

Thanks for confirming. The integer limitation seems a bit strange. Iwould think that a window join on datetimes would be the most commonapplication.Having the function silently drop the fractional values rather thanthrow an error is particularly dang...

leonbaum2

Thanks, those examples do result in the tables being updated on disk,but the sorting still appears to use as much memory as loading theentire table. I suppose that's the only efficient way to do it.Leonwp writes:> yes:>> // flat table> q)t:([]a:2 1 2...

leonbaum2

Ok, I think I got in now by also doing an asof join on a cross producttable:t1: flip `d`x ! flip (distinct t.d) cross (distinct t.x) select from aj[`x`d;t1;t] where y=(max; y) fby dd x y -----------------2013.01.01 2 1.232013.01.02 1 1.342013.01.03 2...

leonbaum2

Thanks. I think the solution will definitely involve fby, but it's stillmissing the inclusion of the most recent value of "y" for groups thatdon't have a record on a given day.For example, on 2013.01.3, the max should be (2013.01.01; 2; 1.23)because ...

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Infinite tail recursion?

Better way to test all combinations of boolean filters

Strange rank error

Dictionary subset

Null booleans?

Re: Infinite tail recursion?

Re: wj1 rounding issue?

Re: Sorting on disk

Re: Max value asof date across groups

Re: Max value asof date across groups