Q Language looping

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I am new to Q language and trying to figure out its basics. I am trying a sample program in which let’s say for a given number I can find the sum of all the multiples of 3 and 5?

if input is 10 sum : 23

I am trying to think in terms of using functions like til ,sum and each verb but to no avail till now. Any pointers would be helpful

thanks

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GitHub Kimtang Kdb-Euler 01.q

Kim

Sent from my iPhone

3

UNTESTED:

Something like this should work:

sum x where {~&/x mod 3 5} each x:til `int$read0 0

–
Ryan
[ERROR]: Your autotools build scripts are 200 lines longer than your program. Something’s wrong.
http://kirbyfan64.github.io/

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{sum x where ((0=x mod 3) or (0=x mod 5))} til 10

5

Whoops, there were a few mistakes. Here’s a correct version:

where {not &/[x mod 3 5]} each til 20

You can replace 20 with whatever number it is you want.

6

There’s lots of looping done under the covers, but loops are hardly ever used because (as you suggest) we can process lists with verbs and adverbs.

q)1 2 3+1 1 1   /the verb + works on lists
2 3 4

q)(+/)til 4  /and advervs like over (/) make verbs that usually take two nouns reduce a list.
6

Your example is a good test to see how much we can reduce an expression to it’s essential parts:

q)x:til 10;sum x where ((0=x mod 3) or (0=x mod 5))
23
q)x:til 10;sum x where (0=x mod 3) or (0=x mod 5)
23
q)x:til 10;sum x where (or/)(0=x mod 3;0=x mod 5)
23
q)x:til 10;sum x where (or/)0=(x mod 3;x mod 5)
23
q)x:til 10;sum x where (or/)0=(x mod/: 3 5)
23
q)x:til 10;sum x where (or/)(0=x mod/:3 5)
23
q)k)x:!10;+/&|/(0=x .q.mod/:3 5)
23

! is til, +/ is sum, & is where, |/ is (or/)

k doesn’t have a primitive mod verb, so use q’s (.q.mod)

On 26/07/2016 1:46 AM, “Ryan Gonzalez” <rymg19@gmail.com> wrote:

UNTESTED:

Something like this should work:

sum x where {~&/x mod 3 5} each x:til `int$read0 0

–
Ryan
[ERROR]: Your autotools build scripts are 200 lines longer than your program. Something’s wrong.
http://kirbyfan64.github.io/