Re: [Jgeneral] requiring regex on Mac M1 produces a security error
OK, I will make that change. On Tue, Aug 30, 2022 at 1:38 PM Norman Drinkwater wrote: > > Ah, didn't realize that. We should replace the contents of > macos-fix.command with > xattr -rc * > > That should fix the problem. > > On Tue, Aug 30, 2022 at 3:21 PM chris burke wrote: > > > I am a little puzzled by this. Regex is part of the base installation, > > not an addon. Jd has its own copy of regex for historical reasons, but > > this should not be needed by tgsjo. > > > > Is it that the macos-fix.command should also call xattr on > > tools/regex/libjpcre2.dylib? > > > > On Tue, Aug 30, 2022 at 1:04 PM Norman Drinkwater > > wrote: > > > > > > Downloads that use curl to retrieve the file (like package manager) > > > shouldn’t have this issue. If you download a file with a web browser, > > > you’ll need to run xattr from a terminal to clear the extended attribute > > > for the file. See here: > > > > > https://code.jsoftware.com/wiki/Guides/J9_Standalone#macOS_standalone_application > > > > > > > > > On Tue, Aug 30, 2022 at 2:13 PM Brian Schott > > wrote: > > > > > > > I just received a notice from a person wishing to load > > > > '/Users/xxx/j/j903/addons/zerowords/tgsjo' that the regex addon and is > > not > > > > working (see the quoted excerpt below of the person's message). I can > > > > confirm the error message and am able to overcome the problem by > > employing > > > > System Preferences>Security & Privacy> General, but with multiple > > steps. At > > > > the bottom half of the General dialog box there is the option "Allow > > apps > > > > downloaded from:" . I clicked on an option (which is no longer > > showing) to > > > > accept anyway. Then the load in jQt still gives an error which offers > > a NEW > > > > option to Open; I clicked that option. But even then another error > > shows up > > > > during the load process. A repeat NEW load (without even quitting jQt) > > > > succeeds without error. > > > > > > > > So, I am wondering if there is an easier workaround? > > > > > > > > "starting tsgjo.ijs. in the Jqt903. on the Mac M1 raises the following > > > > error: > > > > > > > > libjpcre2.dylib. cannot be opened because the developper cannot be > > > > verified > > > > > > > > > > > > this is obviously a Mac security idiosyncrasy I see that. > > > > libjpcre2.dylib is installed in the addons/data/jd/cd. folder. > > > > " > > > > > > > > -- > > > > (B=) <-my sig > > > > Brian Schott > > > > -- > > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > > > -- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > -- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > -- > For information about J forums see http://www.jsoftware.com/forums.htm -- For information about J forums see http://www.jsoftware.com/forums.htm
Re: [Jgeneral] requiring regex on Mac M1 produces a security error
Ah, didn't realize that. We should replace the contents of macos-fix.command with xattr -rc * That should fix the problem. On Tue, Aug 30, 2022 at 3:21 PM chris burke wrote: > I am a little puzzled by this. Regex is part of the base installation, > not an addon. Jd has its own copy of regex for historical reasons, but > this should not be needed by tgsjo. > > Is it that the macos-fix.command should also call xattr on > tools/regex/libjpcre2.dylib? > > On Tue, Aug 30, 2022 at 1:04 PM Norman Drinkwater > wrote: > > > > Downloads that use curl to retrieve the file (like package manager) > > shouldn’t have this issue. If you download a file with a web browser, > > you’ll need to run xattr from a terminal to clear the extended attribute > > for the file. See here: > > > https://code.jsoftware.com/wiki/Guides/J9_Standalone#macOS_standalone_application > > > > > > On Tue, Aug 30, 2022 at 2:13 PM Brian Schott > wrote: > > > > > I just received a notice from a person wishing to load > > > '/Users/xxx/j/j903/addons/zerowords/tgsjo' that the regex addon and is > not > > > working (see the quoted excerpt below of the person's message). I can > > > confirm the error message and am able to overcome the problem by > employing > > > System Preferences>Security & Privacy> General, but with multiple > steps. At > > > the bottom half of the General dialog box there is the option "Allow > apps > > > downloaded from:" . I clicked on an option (which is no longer > showing) to > > > accept anyway. Then the load in jQt still gives an error which offers > a NEW > > > option to Open; I clicked that option. But even then another error > shows up > > > during the load process. A repeat NEW load (without even quitting jQt) > > > succeeds without error. > > > > > > So, I am wondering if there is an easier workaround? > > > > > > "starting tsgjo.ijs. in the Jqt903. on the Mac M1 raises the following > > > error: > > > > > > libjpcre2.dylib. cannot be opened because the developper cannot be > > > verified > > > > > > > > > this is obviously a Mac security idiosyncrasy I see that. > > > libjpcre2.dylib is installed in the addons/data/jd/cd. folder. > > > " > > > > > > -- > > > (B=) <-my sig > > > Brian Schott > > > -- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > > -- > > For information about J forums see http://www.jsoftware.com/forums.htm > -- > For information about J forums see http://www.jsoftware.com/forums.htm > -- For information about J forums see http://www.jsoftware.com/forums.htm
Re: [Jgeneral] requiring regex on Mac M1 produces a security error
I am a little puzzled by this. Regex is part of the base installation, not an addon. Jd has its own copy of regex for historical reasons, but this should not be needed by tgsjo. Is it that the macos-fix.command should also call xattr on tools/regex/libjpcre2.dylib? On Tue, Aug 30, 2022 at 1:04 PM Norman Drinkwater wrote: > > Downloads that use curl to retrieve the file (like package manager) > shouldn’t have this issue. If you download a file with a web browser, > you’ll need to run xattr from a terminal to clear the extended attribute > for the file. See here: > https://code.jsoftware.com/wiki/Guides/J9_Standalone#macOS_standalone_application > > > On Tue, Aug 30, 2022 at 2:13 PM Brian Schott wrote: > > > I just received a notice from a person wishing to load > > '/Users/xxx/j/j903/addons/zerowords/tgsjo' that the regex addon and is not > > working (see the quoted excerpt below of the person's message). I can > > confirm the error message and am able to overcome the problem by employing > > System Preferences>Security & Privacy> General, but with multiple steps. At > > the bottom half of the General dialog box there is the option "Allow apps > > downloaded from:" . I clicked on an option (which is no longer showing) to > > accept anyway. Then the load in jQt still gives an error which offers a NEW > > option to Open; I clicked that option. But even then another error shows up > > during the load process. A repeat NEW load (without even quitting jQt) > > succeeds without error. > > > > So, I am wondering if there is an easier workaround? > > > > "starting tsgjo.ijs. in the Jqt903. on the Mac M1 raises the following > > error: > > > > libjpcre2.dylib. cannot be opened because the developper cannot be > > verified > > > > > > this is obviously a Mac security idiosyncrasy I see that. > > libjpcre2.dylib is installed in the addons/data/jd/cd. folder. > > " > > > > -- > > (B=) <-my sig > > Brian Schott > > -- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > -- > For information about J forums see http://www.jsoftware.com/forums.htm -- For information about J forums see http://www.jsoftware.com/forums.htm
Re: [Jgeneral] requiring regex on Mac M1 produces a security error
Downloads that use curl to retrieve the file (like package manager) shouldn’t have this issue. If you download a file with a web browser, you’ll need to run xattr from a terminal to clear the extended attribute for the file. See here: https://code.jsoftware.com/wiki/Guides/J9_Standalone#macOS_standalone_application On Tue, Aug 30, 2022 at 2:13 PM Brian Schott wrote: > I just received a notice from a person wishing to load > '/Users/xxx/j/j903/addons/zerowords/tgsjo' that the regex addon and is not > working (see the quoted excerpt below of the person's message). I can > confirm the error message and am able to overcome the problem by employing > System Preferences>Security & Privacy> General, but with multiple steps. At > the bottom half of the General dialog box there is the option "Allow apps > downloaded from:" . I clicked on an option (which is no longer showing) to > accept anyway. Then the load in jQt still gives an error which offers a NEW > option to Open; I clicked that option. But even then another error shows up > during the load process. A repeat NEW load (without even quitting jQt) > succeeds without error. > > So, I am wondering if there is an easier workaround? > > "starting tsgjo.ijs. in the Jqt903. on the Mac M1 raises the following > error: > > libjpcre2.dylib. cannot be opened because the developper cannot be > verified > > > this is obviously a Mac security idiosyncrasy I see that. > libjpcre2.dylib is installed in the addons/data/jd/cd. folder. > " > > -- > (B=) <-my sig > Brian Schott > -- > For information about J forums see http://www.jsoftware.com/forums.htm > -- For information about J forums see http://www.jsoftware.com/forums.htm
[Jgeneral] requiring regex on Mac M1 produces a security error
I just received a notice from a person wishing to load '/Users/xxx/j/j903/addons/zerowords/tgsjo' that the regex addon and is not working (see the quoted excerpt below of the person's message). I can confirm the error message and am able to overcome the problem by employing System Preferences>Security & Privacy> General, but with multiple steps. At the bottom half of the General dialog box there is the option "Allow apps downloaded from:" . I clicked on an option (which is no longer showing) to accept anyway. Then the load in jQt still gives an error which offers a NEW option to Open; I clicked that option. But even then another error shows up during the load process. A repeat NEW load (without even quitting jQt) succeeds without error. So, I am wondering if there is an easier workaround? "starting tsgjo.ijs. in the Jqt903. on the Mac M1 raises the following error: libjpcre2.dylib. cannot be opened because the developper cannot be verified this is obviously a Mac security idiosyncrasy I see that. libjpcre2.dylib is installed in the addons/data/jd/cd. folder. " -- (B=) <-my sig Brian Schott -- For information about J forums see http://www.jsoftware.com/forums.htm
Re: [Jgeneral] i. into the middle of an array.
Indeed we are. It turns out that = or E. is relatively slow on large y (if we
only care about the first few matches), and thus motivating all of our
shenanigans.
On Tuesday, August 30, 2022 at 02:15:19 p.m. EDT, Richard Donovan
wrote:
Are you trying to do this?
3 { I. 'b' = 'aaacc' NB. Find index of third b
10
2 { I. 'c' = 'aaacc' NB. Find index of second c
13
> On 30 Aug 2022, at 17:57, 'Michael Day' via General
> wrote:
>
> Pascal Jasmin's findxth benefits greatly from this tweak:
>
> findxtha =: 4 : 0
> 'x m' =. xm x NB. m is sorted list of find indexes. x is match value.
> if. 0 = #m do. m =. 0 end.
> acc =. i.0
> oset =. 0
> for_i. i. >./ m do.
> idx =. x i.~ oset }. y NB. WAS idx =. x i.~ y
> if. idx = oset -~ # y do. acc return. end.
> if. i e. m do. acc =. acc , oset + idx end.
> oset =. oset + >: idx
> NB. y =. (>: idx) }. y NB. Better NOT to do this!
> end.
> acc , oset + x i.~ oset }. y
> )
>
> (100; 0 2) (findxth -: findxtha) A
> 1
> 100 find2 A NB. (One of) Raul's original suggestions
> 1599
> (100; 0 1 2) ( findxtha) A
> 990 1599 2797
>
> NB. These comparisons partly reproduce/endorse Devon's findings
> NB. but also look at findxth and a couple of variants...
>
> ts =:6!:2 , 7!:2@]
>
> ts'100 (1{I.@E.) A NB. Fails if there’s no (second) 100 in A' NB. My
>early offering!
> 0.512366 8.39904e6
> ts'100 find2 A' NB. (One of) Raul's original suggestions
> 4.1e_6 1280
> ts'(100;0 1 2) findxth A'
> 0.708966 2.14749e9
> ts'(100;0 1 2) findxtha A'
> 2.46e_5 2304
>
> ts'0 1 2 findxthdg 100; A' NB. Don's proposal (renamed here)
> 0.232047 1.35533e8
>
>
> (All these in J904 under Windows 11 on this laptop.)
>
> Not surprisingly, (100; 99494) findxth A is really slow - I interrupted it!
>
>
> So it looks as if Raul's best to stick to one of his original methods,
>
> especially since he points out that the Pritchard sieve only requires
>
> an index of the second instance.
>
>
> Cheers,
>
>
> Mike
>
>
>> On 30/08/2022 15:04, Don Guinn wrote:
>> Oops! should have been
>>
>> timespacex '100 findxth 1;A'
>>
>> 0.0925588 1.35533e8
>>
>>
>>
>>> On Tue, Aug 30, 2022 at 8:02 AM Don Guinn wrote:
>>>
>>> NB. Find the index of some instance of a value
>>>
>>> findxth=:4 : 0
>>>
>>> 'value list'=.y
>>>
>>> try. x{,4$.$.value=list
>>>
>>> catch. _1
>>>
>>> end.
>>>
>>> )
>>>
>>> _20,\z=:?.100#10
>>>
>>> 4 6 8 6 5 8 6 6 6 9 3 2 3 1 9 2 7 0 9 5
>>>
>>> 7 7 9 7 4 8 7 4 2 1 1 0 4 3 9 3 2 7 4 4
>>>
>>> 0 3 7 5 9 6 3 2 8 2 0 3 5 4 0 0 3 1 5 0
>>>
>>> 4 0 2 9 2 4 0 0 7 7 5 7 3 1 6 3 1 5 8 9
>>>
>>> 8 5 3 9 9 8 9 5 1 1 0 4 1 7 3 2 3 4 0 4
>>>
>>> NB. Find index of the second occurence of 2
>>>
>>> 1 findxth 2;z
>>>
>>> 15
>>>
>>> NB. Find index of the third from last of 7
>>>
>>> _3 findxth 7;z
>>>
>>> 69
>>>
>>> NB. Try to find index of the tenth of 5 but does not exist
>>>
>>> 9 findxth 5;z
>>>
>>> _1
>>>
>>> NB. find the index of the middle or next to middle 8
>>>
>>> ({~<.@-:@#),4$.$.8=z
>>>
>>> 48
>>>
>>> A=. ?. 1e8#1e3
>>>
>>> 100 (2 i.~ +/\)@:E. A
>>>
>>> 1599
>>>
>>> timespacex '100 (2 i.~ +/\)@:E. A'
>>>
>>> 0.213069 1.20796e9
>>>
>>> timespacex '100 findxth 2;A'
>>>
>>> 0.0890775 1.35533e8
>>>
>>>
>>> On Mon, Aug 29, 2022 at 6:32 PM 'Pascal Jasmin' via General <
>>> gene...@jsoftware.com> wrote:
>>>
I thought that perhaps this could be fast:
A=. ?. 1e8#1e3
timespacex '100 (2 i.~ +/\)@:E. A' NB. or = instead of E.
0.460527 1.20796e9
This application happens to everyone at least once, if
(u { I.@E.)
had special code where the result of u (or simply m) is presumed (for
speed optimization) to be a list/atom of top (rather than last) occurrences
of matches.
Here is a dyad that returns the xth occurrences (indexes) of x in y if
they exist. where x is in format x (, or ;) m where m is the list of
indexes requested.
It is a bit slow due to the y =. n }. y step.
xm =: {. , }. NB. split arguments as head ; tail. assignment as
'h t' =. xm y
findxth =: 4 : 0
'x m' =. xm x NB. m is sorted list of find indexes. x is match value.
if. 0 = #m do. m =. 0 end.
acc =. i.0
oset =. 0
for_i. i. >./ m do.
idx =. x i.~ y
if. idx = # y do. acc return. end.
if. i e. m do. acc =. acc , oset + idx end.
oset =. oset + >: idx
y =. (>: idx) }. y
end.
acc , oset + x i.~ y
)
1 1 3 4 6 findxth 0 1 0 0 1 0 1 1 1
4 7 8
(1 ; 1 3 4 6) findxth 0 1 0 0 1 0 1 1 1
4 7 8
1 findxth 0 1 0 0 1 0 1 1 1
1 NB. m is 0 (first item) if omitted.
5 {. 100 I.@E. A
990 1599 2797 4550 5073
100 0 1 4 findxth A
990 1599 5073
On
Re: [Jgeneral] i. into the middle of an array.
Are you trying to do this?
3 { I. 'b' = 'aaacc' NB. Find index of third b
10
2 { I. 'c' = 'aaacc' NB. Find index of second c
13
> On 30 Aug 2022, at 17:57, 'Michael Day' via General
> wrote:
>
> Pascal Jasmin's findxth benefits greatly from this tweak:
>
> findxtha =: 4 : 0
> 'x m' =. xm x NB. m is sorted list of find indexes. x is match value.
> if. 0 = #m do. m =. 0 end.
> acc =. i.0
> oset =. 0
> for_i. i. >./ m do.
> idx =. x i.~ oset }. y NB. WAS idx =. x i.~ y
> if. idx = oset -~ # y do. acc return. end.
> if. i e. m do. acc =. acc , oset + idx end.
> oset =. oset + >: idx
> NB. y =. (>: idx) }. y NB. Better NOT to do this!
> end.
> acc , oset + x i.~ oset }. y
> )
>
> (100; 0 2) (findxth -: findxtha) A
> 1
>100 find2 ANB. (One of) Raul's original suggestions
> 1599
>(100; 0 1 2) ( findxtha) A
> 990 1599 2797
>
> NB. These comparisons partly reproduce/endorse Devon's findings
> NB. but also look at findxth and a couple of variants...
>
> ts =:6!:2 , 7!:2@]
>
>ts'100 (1{I.@E.) A NB. Fails if there’s no (second) 100 in A' NB. My
> early offering!
> 0.512366 8.39904e6
>ts'100 find2 A'NB. (One of) Raul's original suggestions
> 4.1e_6 1280
>ts'(100;0 1 2) findxth A'
> 0.708966 2.14749e9
>ts'(100;0 1 2) findxtha A'
> 2.46e_5 2304
>
>ts'0 1 2 findxthdg 100; A' NB. Don's proposal (renamed here)
> 0.232047 1.35533e8
>
>
> (All these in J904 under Windows 11 on this laptop.)
>
> Not surprisingly, (100; 99494) findxth A is really slow - I interrupted it!
>
>
> So it looks as if Raul's best to stick to one of his original methods,
>
> especially since he points out that the Pritchard sieve only requires
>
> an index of the second instance.
>
>
> Cheers,
>
>
> Mike
>
>
>> On 30/08/2022 15:04, Don Guinn wrote:
>> Oops! should have been
>>
>> timespacex '100 findxth 1;A'
>>
>> 0.0925588 1.35533e8
>>
>>
>>
>>> On Tue, Aug 30, 2022 at 8:02 AM Don Guinn wrote:
>>>
>>> NB. Find the index of some instance of a value
>>>
>>> findxth=:4 : 0
>>>
>>> 'value list'=.y
>>>
>>> try. x{,4$.$.value=list
>>>
>>> catch. _1
>>>
>>> end.
>>>
>>> )
>>>
>>> _20,\z=:?.100#10
>>>
>>> 4 6 8 6 5 8 6 6 6 9 3 2 3 1 9 2 7 0 9 5
>>>
>>> 7 7 9 7 4 8 7 4 2 1 1 0 4 3 9 3 2 7 4 4
>>>
>>> 0 3 7 5 9 6 3 2 8 2 0 3 5 4 0 0 3 1 5 0
>>>
>>> 4 0 2 9 2 4 0 0 7 7 5 7 3 1 6 3 1 5 8 9
>>>
>>> 8 5 3 9 9 8 9 5 1 1 0 4 1 7 3 2 3 4 0 4
>>>
>>> NB. Find index of the second occurence of 2
>>>
>>> 1 findxth 2;z
>>>
>>> 15
>>>
>>> NB. Find index of the third from last of 7
>>>
>>> _3 findxth 7;z
>>>
>>> 69
>>>
>>> NB. Try to find index of the tenth of 5 but does not exist
>>>
>>> 9 findxth 5;z
>>>
>>> _1
>>>
>>> NB. find the index of the middle or next to middle 8
>>>
>>> ({~<.@-:@#),4$.$.8=z
>>>
>>> 48
>>>
>>> A=. ?. 1e8#1e3
>>>
>>> 100 (2 i.~ +/\)@:E. A
>>>
>>> 1599
>>>
>>> timespacex '100 (2 i.~ +/\)@:E. A'
>>>
>>> 0.213069 1.20796e9
>>>
>>> timespacex '100 findxth 2;A'
>>>
>>> 0.0890775 1.35533e8
>>>
>>>
>>> On Mon, Aug 29, 2022 at 6:32 PM 'Pascal Jasmin' via General <
>>> gene...@jsoftware.com> wrote:
>>>
I thought that perhaps this could be fast:
A=. ?. 1e8#1e3
timespacex '100 (2 i.~ +/\)@:E. A' NB. or = instead of E.
0.460527 1.20796e9
This application happens to everyone at least once, if
(u { I.@E.)
had special code where the result of u (or simply m) is presumed (for
speed optimization) to be a list/atom of top (rather than last) occurrences
of matches.
Here is a dyad that returns the xth occurrences (indexes) of x in y if
they exist. where x is in format x (, or ;) m where m is the list of
indexes requested.
It is a bit slow due to the y =. n }. y step.
xm =: {. , }. NB. split arguments as head ; tail. assignment as
'h t' =. xm y
findxth =: 4 : 0
'x m' =. xm x NB. m is sorted list of find indexes. x is match value.
if. 0 = #m do. m =. 0 end.
acc =. i.0
oset =. 0
for_i. i. >./ m do.
idx =. x i.~ y
if. idx = # y do. acc return. end.
if. i e. m do. acc =. acc , oset + idx end.
oset =. oset + >: idx
y =. (>: idx) }. y
end.
acc , oset + x i.~ y
)
1 1 3 4 6 findxth 0 1 0 0 1 0 1 1 1
4 7 8
(1 ; 1 3 4 6) findxth 0 1 0 0 1 0 1 1 1
4 7 8
1 findxth 0 1 0 0 1 0 1 1 1
1 NB. m is 0 (first item) if omitted.
5 {. 100 I.@E. A
990 1599 2797 4550 5073
100 0 1 4 findxth A
990 1599 5073
On Friday, August 26, 2022 at 05:27:46 p.m. EDT, Devon McCormick <
devon...@gmail.com> wrote:
I get these timings on J 9.04:
A=. ?1e8#1e3
ts '100 find2 A'
2.4e_6 1536
ts '100
Re: [Jgeneral] i. into the middle of an array.
Pascal Jasmin's findxth benefits greatly from this tweak:
findxtha =: 4 : 0
'x m' =. xm x NB. m is sorted list of find indexes. x is match value.
if. 0 = #m do. m =. 0 end.
acc =. i.0
oset =. 0
for_i. i. >./ m do.
idx =. x i.~ oset }. y NB. WAS idx =. x i.~ y
if. idx = oset -~ # y do. acc return. end.
if. i e. m do. acc =. acc , oset + idx end.
oset =. oset + >: idx
NB. y =. (>: idx) }. y NB. Better NOT to do this!
end.
acc , oset + x i.~ oset }. y
)
(100; 0 2) (findxth -: findxtha) A
1
100 find2 A NB. (One of) Raul's original suggestions
1599
(100; 0 1 2) ( findxtha) A
990 1599 2797
NB. These comparisons partly reproduce/endorse Devon's findings
NB. but also look at findxth and a couple of variants...
ts =:6!:2 , 7!:2@]
ts'100 (1{I.@E.) A NB. Fails if there’s no (second) 100 in A' NB.
My early offering!
0.512366 8.39904e6
ts'100 find2 A' NB. (One of) Raul's original suggestions
4.1e_6 1280
ts'(100;0 1 2) findxth A'
0.708966 2.14749e9
ts'(100;0 1 2) findxtha A'
2.46e_5 2304
ts'0 1 2 findxthdg 100; A' NB. Don's proposal (renamed here)
0.232047 1.35533e8
(All these in J904 under Windows 11 on this laptop.)
Not surprisingly, (100; 99494) findxth A is really slow - I interrupted
it!
So it looks as if Raul's best to stick to one of his original methods,
especially since he points out that the Pritchard sieve only requires
an index of the second instance.
Cheers,
Mike
On 30/08/2022 15:04, Don Guinn wrote:
Oops! should have been
timespacex '100 findxth 1;A'
0.0925588 1.35533e8
On Tue, Aug 30, 2022 at 8:02 AM Don Guinn wrote:
NB. Find the index of some instance of a value
findxth=:4 : 0
'value list'=.y
try. x{,4$.$.value=list
catch. _1
end.
)
_20,\z=:?.100#10
4 6 8 6 5 8 6 6 6 9 3 2 3 1 9 2 7 0 9 5
7 7 9 7 4 8 7 4 2 1 1 0 4 3 9 3 2 7 4 4
0 3 7 5 9 6 3 2 8 2 0 3 5 4 0 0 3 1 5 0
4 0 2 9 2 4 0 0 7 7 5 7 3 1 6 3 1 5 8 9
8 5 3 9 9 8 9 5 1 1 0 4 1 7 3 2 3 4 0 4
NB. Find index of the second occurence of 2
1 findxth 2;z
15
NB. Find index of the third from last of 7
_3 findxth 7;z
69
NB. Try to find index of the tenth of 5 but does not exist
9 findxth 5;z
_1
NB. find the index of the middle or next to middle 8
({~<.@-:@#),4$.$.8=z
48
A=. ?. 1e8#1e3
100 (2 i.~ +/\)@:E. A
1599
timespacex '100 (2 i.~ +/\)@:E. A'
0.213069 1.20796e9
timespacex '100 findxth 2;A'
0.0890775 1.35533e8
On Mon, Aug 29, 2022 at 6:32 PM 'Pascal Jasmin' via General <
gene...@jsoftware.com> wrote:
I thought that perhaps this could be fast:
A=. ?. 1e8#1e3
timespacex '100 (2 i.~ +/\)@:E. A' NB. or = instead of E.
0.460527 1.20796e9
This application happens to everyone at least once, if
(u { I.@E.)
had special code where the result of u (or simply m) is presumed (for
speed optimization) to be a list/atom of top (rather than last) occurrences
of matches.
Here is a dyad that returns the xth occurrences (indexes) of x in y if
they exist. where x is in format x (, or ;) m where m is the list of
indexes requested.
It is a bit slow due to the y =. n }. y step.
xm =: {. , }. NB. split arguments as head ; tail. assignment as
'h t' =. xm y
findxth =: 4 : 0
'x m' =. xm x NB. m is sorted list of find indexes. x is match value.
if. 0 = #m do. m =. 0 end.
acc =. i.0
oset =. 0
for_i. i. >./ m do.
idx =. x i.~ y
if. idx = # y do. acc return. end.
if. i e. m do. acc =. acc , oset + idx end.
oset =. oset + >: idx
y =. (>: idx) }. y
end.
acc , oset + x i.~ y
)
1 1 3 4 6 findxth 0 1 0 0 1 0 1 1 1
4 7 8
(1 ; 1 3 4 6) findxth 0 1 0 0 1 0 1 1 1
4 7 8
1 findxth 0 1 0 0 1 0 1 1 1
1 NB. m is 0 (first item) if omitted.
5 {. 100 I.@E. A
990 1599 2797 4550 5073
100 0 1 4 findxth A
990 1599 5073
On Friday, August 26, 2022 at 05:27:46 p.m. EDT, Devon McCormick <
devon...@gmail.com> wrote:
I get these timings on J 9.04:
A=. ?1e8#1e3
ts '100 find2 A'
2.4e_6 1536
ts '100 (1{I.@E.) A'
0.19722 8.39853e6
ts '100 ({.@}.@(I.@E.)) A'
0.200139 8.39866e6
(100 find2 A) -: 100 (1{I.@E.) A
1
find2
([: >: i.~) + [ i.~ ] }.~ [: >: i.~
On Fri, Aug 26, 2022 at 3:53 PM 'Mike Day' via General <
gene...@jsoftware.com> wrote:
Does that include drop, }. ? I suppose it can, since we only need to
move the pointer to the start... I’ll check on the laptop, once I’ve
done
my Listener xwd.
(Last week’s was the quarterly numeric puzzle, an ingenious
construction
including among all the digits a few decimal points and solidus ( / )
for
rationals!)
Cheers,
Mike
Sent from my iPad
On 26 Aug 2022, at 20:36, Raul Miller wrote:
Updating arrays without generating a new copy was introduce in J805 --
https://code.jsoftware.com/wiki/System/ReleaseNotes/J805
So in J701, that approach would indeed be slower (since it's creating
a complete copy of the array).
Also, virtual blocks (which speed up the }. approach) were introduced
in J807. I guess I need to roll up my sleeves and do some
benchmarking...
Thanks,
--
Raul
On Fri, Aug 26, 2022
Re: [Jgeneral] i. into the middle of an array.
Don's better implementation than mine for finding an arbitrary repeat occurrence still does that (find 2nd) On Tuesday, August 30, 2022 at 10:49:14 a.m. EDT, Raul Miller wrote: On Tue, Aug 30, 2022 at 10:05 AM Don Guinn wrote: > Oops! should have been > > timespacex '100 findxth 1;A' > 0.0925588 1.35533e8 For what it's worth, the context here was specifically finding the second instance of a value. https://rosettacode.org/wiki/Sieve_of_Pritchard#J Thanks, -- Raul -- For information about J forums see http://www.jsoftware.com/forums.htm -- For information about J forums see http://www.jsoftware.com/forums.htm
Re: [Jgeneral] i. into the middle of an array.
On Tue, Aug 30, 2022 at 10:05 AM Don Guinn wrote: > Oops! should have been > > timespacex '100 findxth 1;A' > 0.0925588 1.35533e8 For what it's worth, the context here was specifically finding the second instance of a value. https://rosettacode.org/wiki/Sieve_of_Pritchard#J Thanks, -- Raul -- For information about J forums see http://www.jsoftware.com/forums.htm
Re: [Jgeneral] i. into the middle of an array.
Oops! should have been
timespacex '100 findxth 1;A'
0.0925588 1.35533e8
On Tue, Aug 30, 2022 at 8:02 AM Don Guinn wrote:
> NB. Find the index of some instance of a value
>
> findxth=:4 : 0
>
> 'value list'=.y
>
> try. x{,4$.$.value=list
>
> catch. _1
>
> end.
>
> )
>
> _20,\z=:?.100#10
>
> 4 6 8 6 5 8 6 6 6 9 3 2 3 1 9 2 7 0 9 5
>
> 7 7 9 7 4 8 7 4 2 1 1 0 4 3 9 3 2 7 4 4
>
> 0 3 7 5 9 6 3 2 8 2 0 3 5 4 0 0 3 1 5 0
>
> 4 0 2 9 2 4 0 0 7 7 5 7 3 1 6 3 1 5 8 9
>
> 8 5 3 9 9 8 9 5 1 1 0 4 1 7 3 2 3 4 0 4
>
> NB. Find index of the second occurence of 2
>
> 1 findxth 2;z
>
> 15
>
> NB. Find index of the third from last of 7
>
> _3 findxth 7;z
>
> 69
>
> NB. Try to find index of the tenth of 5 but does not exist
>
> 9 findxth 5;z
>
> _1
>
> NB. find the index of the middle or next to middle 8
>
> ({~<.@-:@#),4$.$.8=z
>
> 48
>
> A=. ?. 1e8#1e3
>
> 100 (2 i.~ +/\)@:E. A
>
> 1599
>
> timespacex '100 (2 i.~ +/\)@:E. A'
>
> 0.213069 1.20796e9
>
> timespacex '100 findxth 2;A'
>
> 0.0890775 1.35533e8
>
>
> On Mon, Aug 29, 2022 at 6:32 PM 'Pascal Jasmin' via General <
> gene...@jsoftware.com> wrote:
>
>> I thought that perhaps this could be fast:
>>
>> A=. ?. 1e8#1e3
>>
>> timespacex '100 (2 i.~ +/\)@:E. A' NB. or = instead of E.
>> 0.460527 1.20796e9
>>
>>
>> This application happens to everyone at least once, if
>>
>> (u { I.@E.)
>>
>> had special code where the result of u (or simply m) is presumed (for
>> speed optimization) to be a list/atom of top (rather than last) occurrences
>> of matches.
>>
>>
>> Here is a dyad that returns the xth occurrences (indexes) of x in y if
>> they exist. where x is in format x (, or ;) m where m is the list of
>> indexes requested.
>>
>> It is a bit slow due to the y =. n }. y step.
>>
>> xm =: {. , }. NB. split arguments as head ; tail. assignment as
>> 'h t' =. xm y
>>
>> findxth =: 4 : 0
>>
>> 'x m' =. xm x NB. m is sorted list of find indexes. x is match value.
>> if. 0 = #m do. m =. 0 end.
>> acc =. i.0
>> oset =. 0
>>
>> for_i. i. >./ m do.
>>
>> idx =. x i.~ y
>>
>> if. idx = # y do. acc return. end.
>>
>> if. i e. m do. acc =. acc , oset + idx end.
>>
>> oset =. oset + >: idx
>>
>> y =. (>: idx) }. y
>>
>> end.
>>
>> acc , oset + x i.~ y
>>
>> )
>>
>> 1 1 3 4 6 findxth 0 1 0 0 1 0 1 1 1
>>
>> 4 7 8
>>
>> (1 ; 1 3 4 6) findxth 0 1 0 0 1 0 1 1 1
>>
>> 4 7 8
>>
>> 1 findxth 0 1 0 0 1 0 1 1 1
>>
>> 1 NB. m is 0 (first item) if omitted.
>>
>>
>> 5 {. 100 I.@E. A
>>
>> 990 1599 2797 4550 5073
>>
>> 100 0 1 4 findxth A
>>
>> 990 1599 5073
>>
>>
>> On Friday, August 26, 2022 at 05:27:46 p.m. EDT, Devon McCormick <
>> devon...@gmail.com> wrote:
>>
>>
>>
>>
>>
>> I get these timings on J 9.04:
>>
>> A=. ?1e8#1e3
>> ts '100 find2 A'
>> 2.4e_6 1536
>> ts '100 (1{I.@E.) A'
>> 0.19722 8.39853e6
>> ts '100 ({.@}.@(I.@E.)) A'
>> 0.200139 8.39866e6
>> (100 find2 A) -: 100 (1{I.@E.) A
>> 1
>> find2
>> ([: >: i.~) + [ i.~ ] }.~ [: >: i.~
>>
>>
>> On Fri, Aug 26, 2022 at 3:53 PM 'Mike Day' via General <
>> gene...@jsoftware.com> wrote:
>>
>> > Does that include drop, }. ? I suppose it can, since we only need to
>> > move the pointer to the start... I’ll check on the laptop, once I’ve
>> done
>> > my Listener xwd.
>> >
>> > (Last week’s was the quarterly numeric puzzle, an ingenious
>> construction
>> > including among all the digits a few decimal points and solidus ( / )
>> for
>> > rationals!)
>> >
>> > Cheers,
>> > Mike
>> >
>> >
>> >
>> > Sent from my iPad
>> >
>> > > On 26 Aug 2022, at 20:36, Raul Miller wrote:
>> > >
>> > > Updating arrays without generating a new copy was introduce in J805 --
>> > > https://code.jsoftware.com/wiki/System/ReleaseNotes/J805
>> > >
>> > > So in J701, that approach would indeed be slower (since it's creating
>> > > a complete copy of the array).
>> > >
>> > > Also, virtual blocks (which speed up the }. approach) were introduced
>> > > in J807. I guess I need to roll up my sleeves and do some
>> > > benchmarking...
>> > >
>> > > Thanks,
>> > >
>> > > --
>> > > Raul
>> > >
>> > > On Fri, Aug 26, 2022 at 3:20 PM 'Mike Day' via General
>> > > wrote:
>> > >>
>> > >> These seem simpler and are possibly quicker, at least in J701 on
>> this
>> > oldish iPad:
>> > >> 100 (1{I.@E.) A NB. Fails if there’s no (second) 100 in A
>> > >> 719
>> > >> 100 ({.@}.@(I.@E.)) A NB. Returns 0 in that case
>> > >> 719
>> > >> Easy to correct for such errors, of course.
>> > >>
>> > >> I tried
>> > >> A =. ?100#1000
>> > >> find2 =: 13 : 'F + ((F=.>:y i. x) }. y) i. x' NB. No direct defs in
>> > J701
>> > >> ts'100 find2 A'
>> > >> 0.020555 8.39091e6
>> > >> ts'100 (1{I.@E.) A'
>> > >> 0.011503 76160
>> > >> ts'100 ({.@}.@(I.@E.)) A'
>> > >> 0.007626 84864
>> > >>
>> > >> Speed a bit better, space quite a lot, if happy with time & space
>> > tests.
>> > >>
>> > >> Only you know if it’s wise to overwrite the first occurrence of V in
>> A!
>> > >>
>> > >> Cheers,
>> > >>
>> > >> Mike
>> > >>
>> > >>
>> > >>
>> > >> Sent from my iPad
>> > >>
>>
Re: [Jgeneral] i. into the middle of an array.
NB. Find the index of some instance of a value
findxth=:4 : 0
'value list'=.y
try. x{,4$.$.value=list
catch. _1
end.
)
_20,\z=:?.100#10
4 6 8 6 5 8 6 6 6 9 3 2 3 1 9 2 7 0 9 5
7 7 9 7 4 8 7 4 2 1 1 0 4 3 9 3 2 7 4 4
0 3 7 5 9 6 3 2 8 2 0 3 5 4 0 0 3 1 5 0
4 0 2 9 2 4 0 0 7 7 5 7 3 1 6 3 1 5 8 9
8 5 3 9 9 8 9 5 1 1 0 4 1 7 3 2 3 4 0 4
NB. Find index of the second occurence of 2
1 findxth 2;z
15
NB. Find index of the third from last of 7
_3 findxth 7;z
69
NB. Try to find index of the tenth of 5 but does not exist
9 findxth 5;z
_1
NB. find the index of the middle or next to middle 8
({~<.@-:@#),4$.$.8=z
48
A=. ?. 1e8#1e3
100 (2 i.~ +/\)@:E. A
1599
timespacex '100 (2 i.~ +/\)@:E. A'
0.213069 1.20796e9
timespacex '100 findxth 2;A'
0.0890775 1.35533e8
On Mon, Aug 29, 2022 at 6:32 PM 'Pascal Jasmin' via General <
gene...@jsoftware.com> wrote:
> I thought that perhaps this could be fast:
>
> A=. ?. 1e8#1e3
>
> timespacex '100 (2 i.~ +/\)@:E. A' NB. or = instead of E.
> 0.460527 1.20796e9
>
>
> This application happens to everyone at least once, if
>
> (u { I.@E.)
>
> had special code where the result of u (or simply m) is presumed (for
> speed optimization) to be a list/atom of top (rather than last) occurrences
> of matches.
>
>
> Here is a dyad that returns the xth occurrences (indexes) of x in y if
> they exist. where x is in format x (, or ;) m where m is the list of
> indexes requested.
>
> It is a bit slow due to the y =. n }. y step.
>
> xm =: {. , }. NB. split arguments as head ; tail. assignment as 'h
> t' =. xm y
>
> findxth =: 4 : 0
>
> 'x m' =. xm x NB. m is sorted list of find indexes. x is match value.
> if. 0 = #m do. m =. 0 end.
> acc =. i.0
> oset =. 0
>
> for_i. i. >./ m do.
>
> idx =. x i.~ y
>
> if. idx = # y do. acc return. end.
>
> if. i e. m do. acc =. acc , oset + idx end.
>
> oset =. oset + >: idx
>
> y =. (>: idx) }. y
>
> end.
>
> acc , oset + x i.~ y
>
> )
>
> 1 1 3 4 6 findxth 0 1 0 0 1 0 1 1 1
>
> 4 7 8
>
> (1 ; 1 3 4 6) findxth 0 1 0 0 1 0 1 1 1
>
> 4 7 8
>
> 1 findxth 0 1 0 0 1 0 1 1 1
>
> 1 NB. m is 0 (first item) if omitted.
>
>
> 5 {. 100 I.@E. A
>
> 990 1599 2797 4550 5073
>
> 100 0 1 4 findxth A
>
> 990 1599 5073
>
>
> On Friday, August 26, 2022 at 05:27:46 p.m. EDT, Devon McCormick <
> devon...@gmail.com> wrote:
>
>
>
>
>
> I get these timings on J 9.04:
>
> A=. ?1e8#1e3
> ts '100 find2 A'
> 2.4e_6 1536
> ts '100 (1{I.@E.) A'
> 0.19722 8.39853e6
> ts '100 ({.@}.@(I.@E.)) A'
> 0.200139 8.39866e6
> (100 find2 A) -: 100 (1{I.@E.) A
> 1
> find2
> ([: >: i.~) + [ i.~ ] }.~ [: >: i.~
>
>
> On Fri, Aug 26, 2022 at 3:53 PM 'Mike Day' via General <
> gene...@jsoftware.com> wrote:
>
> > Does that include drop, }. ? I suppose it can, since we only need to
> > move the pointer to the start... I’ll check on the laptop, once I’ve
> done
> > my Listener xwd.
> >
> > (Last week’s was the quarterly numeric puzzle, an ingenious construction
> > including among all the digits a few decimal points and solidus ( / ) for
> > rationals!)
> >
> > Cheers,
> > Mike
> >
> >
> >
> > Sent from my iPad
> >
> > > On 26 Aug 2022, at 20:36, Raul Miller wrote:
> > >
> > > Updating arrays without generating a new copy was introduce in J805 --
> > > https://code.jsoftware.com/wiki/System/ReleaseNotes/J805
> > >
> > > So in J701, that approach would indeed be slower (since it's creating
> > > a complete copy of the array).
> > >
> > > Also, virtual blocks (which speed up the }. approach) were introduced
> > > in J807. I guess I need to roll up my sleeves and do some
> > > benchmarking...
> > >
> > > Thanks,
> > >
> > > --
> > > Raul
> > >
> > > On Fri, Aug 26, 2022 at 3:20 PM 'Mike Day' via General
> > > wrote:
> > >>
> > >> These seem simpler and are possibly quicker, at least in J701 on this
> > oldish iPad:
> > >> 100 (1{I.@E.) A NB. Fails if there’s no (second) 100 in A
> > >> 719
> > >> 100 ({.@}.@(I.@E.)) A NB. Returns 0 in that case
> > >> 719
> > >> Easy to correct for such errors, of course.
> > >>
> > >> I tried
> > >> A =. ?100#1000
> > >> find2 =: 13 : 'F + ((F=.>:y i. x) }. y) i. x' NB. No direct defs in
> > J701
> > >> ts'100 find2 A'
> > >> 0.020555 8.39091e6
> > >> ts'100 (1{I.@E.) A'
> > >> 0.011503 76160
> > >> ts'100 ({.@}.@(I.@E.)) A'
> > >> 0.007626 84864
> > >>
> > >> Speed a bit better, space quite a lot, if happy with time & space
> > tests.
> > >>
> > >> Only you know if it’s wise to overwrite the first occurrence of V in
> A!
> > >>
> > >> Cheers,
> > >>
> > >> Mike
> > >>
> > >>
> > >>
> > >> Sent from my iPad
> > >>
> > >>> On 26 Aug 2022, at 19:36, Raul Miller wrote:
> > >>>
> > >>> i. returns the index of the first occurrence of a value within an
> > array.
> > >>>
> > >>> So, when implementing an algorithm which needs the index of the
> second
> > >>> occurrence of the value within a (large) array, we need to do some
> > >>> additional work.
> > >>>
> > >>> let's say that our array is A, the value is V
> > >>>
> >
