« first day (1622 days earlier)      last day (1253 days later) » 

LdBeth
LdBeth
02:32
img×(-a)↓a↓{+/,g×⍵}⌺s⊢(⍪⍨⍪⊢)(,⍨,⊢)img
is it possible to improve this computation? it does stencil on a torus by padding. I tried the stencell mentioned in dyalog blog but that gives a WS FULL on 64 64 array.
Bubbler
Bubbler
What is s?
I guess it's convolution size
But I don't expect that to give WS FULL, as (⍪⍨⍪⊢)(,⍨,⊢)img should give a (64×3)(64×3) array which is not that large
LdBeth
LdBeth
s is 1+2×⌊2÷⍨3 5, where img is a 2D array
Bubbler
Bubbler
Btw 1+2×⌊2÷⍨x y is simply x y if x and y are odd
An obvious improvement would be changing (⍪⍨⍪⊢)(,⍨,⊢) to pad just what you need
LdBeth
LdBeth
x y is even.
let me try if trim the padded array would improve the performance
yes, img×(-h)↓(h←a÷2)↓{+/,g×⍵}⌺s⊢(2⊖⍪⍨)(2⌽,⍨)img gives 1 third improvement on performance
thank you for the suggestion
LdBeth
LdBeth
03:05
oh, I made a typo, s is 1+2×⌊2÷⍨⍴img
the roughly same size of img rounded to have odd edge sizes
 
15 hours later…
Adám
Adám
18:25
Job opportunities: Do you like watching APL videos? Check out the two new listings, one for volunteer work and one paid internship!
2

« first day (1622 days earlier)      last day (1253 days later) »