Re: better apl array coding

[enztec]

Hi

thanks for this code - first time actually using ¨ and ⌷

in my comparison test on an old hp dual core linux machine - with only mplayer 
running
with ⍴a and ⍴b 29882 chars

according to ⎕ts   my loop code takes ~39 seconds to put results into rs
2021 6 15 19 46 11 277
2021 6 15 19 46 50 354

and the new code takes ~50 msec to put results into rs1    yes msec vs seconds  
 what is that 39000 msec vs 59 msec
2021 6 15 19 46 50 354
2021 6 15 19 46 50 404

+/rs1=rs    and rs and rs1 don't exist before running them in fns
29882

----

the only problem i have is in a fresh ws running the )copy as

⍎')copy mn9     mn9 is a file which has a string of 29882 chars assigned to 
mn9←'xxxxx' in it
a←mn9             gives mn9 value error consistently - though when i check the 
)vars it is there and complete - running it in ram drive has no effect

the unquoted ')copy'  doesn't actually finish coping the file into the ws as 
fast as the code returns and goes to the next line

no real problem as i usually hard code the sequnces (cutnpaste) into the script 
- but with some in the 100K range i will have to do the )copy manually and run 
in workspace

thank you for giving me this code - much appreciated



On Tue, 15 Jun 2021 15:20:27 +0200
Dr. Jürgen Sauermann <mail@xn--jrgen-sauermann-zvb.de> wrote:

> Hi,
>
> how about:
>
>       (a,¨b)⌷¨⊂ar
> 11 22 33 44 44 33 22 11
>
>
> Best Regards,
> Jürgen
>
>
> On 6/15/21 2:45 AM, enztec@gmx.com wrote:
> hello
>
> i've been using this looping for array work but there has to be a better apl 
> way of coding the indexing of the ar array
> any suggestions
>
>
>
> ∇rs←lp;a;b;ar;i
> 'lp'
> 'ar'
> +ar←4 4⍴11 12 13 14 21 22 23 24 31 32 33 34 41 42 43 44
> 'a '
> +a←1 2 3 4 4 3 2 1
> 'b '
> +b←1 2 3 4 4 3 2 1
> i←1
> rs←⍴0
> sp:
> rs←rs,ar[a[i]; b[i]]
> →((i←i+1)⍴a)/sp
> ''
> ∇
>
>
>