A simpler f:
f=: 13 :'(/:/:y)-(i.~ y){/:/:y'
f
([: /: /:) - i.~ { [: /: /:
Linda
-----Original Message-----
From: Programming [mailto:[email protected]]
On Behalf Of Linda A Alvord
Sent: Wednesday, January 20, 2016 3:15 AM
To: [email protected]
Subject: Re: [Jprogramming] A Different Less?
Here's another way to write the code that so far is the fastest.
How does it compare?
A=:'abcabbe'
B=:'babe'
f=: 13 :'(/:/:y)-(y i. y){/:/:y'
g=: 13 :'((f x)>: (( ~.y)i.x){(#/.~y),0: y)#x'
A g B
cab
f
([: /: /:) - i.~ { [: /: /:
g
[ #~ ([: f [) >: ([ i.~ [: ~. ]) { ([: #/.~ ]) , [: 0: ]
Linda
-----Original Message-----
From: Programming [mailto:[email protected]]
On Behalf Of Raul Miller
Sent: Monday, January 18, 2016 12:51 PM
To: Programming forum
Subject: Re: [Jprogramming] A Different Less?
Hmm...
A bugfixed version of my previous implementation (it broke when x
-. y was empty) performs approximately the same, for me:
cle=: ,~ #~ i.@#@,~ e. [: ; (2*#/.~@]) (}.&.>~ #@[ {. ])~ (]i.,~)
</. i.@#@,~
I say approximately, because timing variations mean that when I
test on the same data, sometimes it's faster and sometimes it's
slower than
oc=: i.~ (] - {) /:@/:
cless =: [ #~ oc@:[ >: (i.~~.) { (#/.~,0:)@]
That said, Boss's implementation is clearly more concise...
Thanks,
--
Raul
On Mon, Jan 18, 2016 at 12:17 PM, Marshall Lochbaum
<[email protected]> wrote:
That's a very cool solution, and much quicker than the one based on
progressive index-of. Instead of taking the occurrence count of
both x
and y, it just takes the count for x and compares it to the total
number of occurrences in y, given by (#/.~).
Here's a comparison of the two methods. It turns out in the version
based on progressive index-of, the desired verb can be obtained just
from replacing (i.) with (-.) and then using the first column of the
result to select from x, so I've used that version.
NB. Shared verb for occurrence count
oc=: i.~ (] - {) /:@/:
NB. Simplified form of what Roger and I posted
cless1 =: [ {~ [: {."1 #@[ ({. -.&(,.oc) }.) [ i. ,
NB. Tacitized R.E. Boss solution
cless2 =: [ #~ oc@:[ >: (i.~~.) { (#/.~,0:)@]
NB. test data
'a b' =. 500 ({.;~}.) +&(1e5 ?@$ 26)&.(a.&i.) 'a'
10 (6!:2) 'a cless1 b'
0.0178952
10 (6!:2) 'a cless2 b'
0.0063745
a (cless1 -: cless2) b
1
To summarize, here's the fastest solution so far:
oc=: i.~ (] - {) /:@/:
cless =: [ #~ oc@:[ >: (i.~~.) { (#/.~,0:)@]
Marshall
On Mon, Jan 18, 2016 at 03:49:46PM +0000, R.E. Boss wrote:
I'm getting old, but still remember my solution, improved by Hui:
http://www.jsoftware.com/pipermail/general/2004-May/017503.html
'abcabbe' strikeb2 'babe'
cab
Curious how it performs compared to the other solutions.
R.E. Boss
-----Original Message-----
From: Programming [mailto:[email protected]]
On Behalf Of June Kim (???)
Sent: maandag 18 januari 2016 5:19
To: Programming forum <[email protected]>
Subject: [Jprogramming] A Different Less?
Hello
I am looking for a verb(cless) that does something similar to
Less(-.) but counting the elimination, for example:
'abcabbe' -. 'abbe'
c
'abcabbe' cless 'babe' NB. get rid of y letters counting the
occurrences
'cab'
It is easier to define such a verb recursively: 'abcabbe' cless
'babe'
equald to 'e' cless~ 'b' cless~ 'a' cless~ 'b' cless~ 'abcabbe'
I think recursive definition isn't a usual J-ic approach.
How would you implement such a verb elegantly(with which I mean
short)?
June
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