I ask because I am shaping an array 65000 by 65000 for ploting LY distances in
Boeing Graph (3D).
> From: [email protected]
> Subject: Programming Digest, Vol 68, Issue 43
> To: [email protected]
> Date: Wed, 25 May 2011 22:22:39 +0800
>
> Send Programming mailing list submissions to
> [email protected]
>
> To subscribe or unsubscribe via the World Wide Web, visit
> http://jsoftware.com/cgi-bin/mailman/listinfo/programming
> or, via email, send a message with subject or body 'help' to
> [email protected]
>
> You can reach the person managing the list at
> [email protected]
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Programming digest..."
>
>
> Today's Topics:
>
> 1. J arrays (Charles Holder)
> 2. Re: J arrays (Roger Hui)
> 3. Sorting (Gian Medri)
> 4. Re: Sorting (Pablo Landherr)
> 5. Re: Sorting (bill lam)
> 6. Re: Sorting (R.E. Boss)
> 7. Re: Sorting (bill lam)
> 8. Re: J arrays (Dan Bron)
> 9. Re: Sorting (Devon McCormick)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 25 May 2011 05:23:23 +0000
> From: Charles Holder <[email protected]>
> Subject: [Jprogramming] J arrays
> To: <[email protected]>
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset="iso-8859-1"
>
>
> What is the max items an array can have?
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 24 May 2011 22:47:47 -0700
> From: Roger Hui <[email protected]>
> Subject: Re: [Jprogramming] J arrays
> To: Programming forum <[email protected]>
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset=us-ascii
>
> _1+2^n-1 where n is the number of bits in a machine word.
> (n is 32 or 64).
>
>
>
> ----- Original Message -----
> From: Charles Holder <[email protected]>
> Date: Tuesday, May 24, 2011 22:24
> Subject: [Jprogramming] J arrays
> To: [email protected]
>
> > What is the max items an array can have?
>
>
>
> ------------------------------
>
> Message: 3
> Date: Wed, 25 May 2011 10:00:42 +0200
> From: Gian Medri <[email protected]>
> Subject: [Jprogramming] Sorting
> To: [email protected]
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset=UTF-8
>
> Hi!
> 1) I have a problem with sorting with the Swedish alphabet that contains 3
> extra letters after z.
> Example:
> /:~'qwe?rta?as?sdf'
> aadefqrsstw??????
>
> Perhaps it depends on the limitation of "a. "?
>
> 2) Often I encounter the necessity to replace element x by element y in an
> array.
> I solved the problem in an APL fashion such as:
> repl=: 4 : '($y)$ (1{x) (((0{x)=,y)#i.*/$y)},y' NB. replace x1 in array y
> by x2
>
> This verb works OK for any array, but I wonder if there is a better J-way
> to do it.
>
> Thanks
> Gian Medri
>
>
> ------------------------------
>
> Message: 4
> Date: Wed, 25 May 2011 10:38:04 +0200
> From: Pablo Landherr <[email protected]>
> Subject: Re: [Jprogramming] Sorting
> To: Programming forum <[email protected]>
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset=UTF-8
>
> And I get
>
> 'qwe?rta?as?sdf'/:'abcdefghijklmnopqrstuvwxyz???' i. 'qwe?rta?as?sdf'
> aadefqrsstw?
> 9!:14 ''
> j602/2008-03-03/16:45
>
> On Wed, May 25, 2011 at 10:00 AM, Gian Medri <[email protected]> wrote:
>
> > Hi!
> > 1) I have a problem with sorting with the Swedish alphabet that contains 3
> > extra letters after z.
> > Example:
> > /:~'qwe?rta?as?sdf'
> > aadefqrsstw??????
> >
> > Perhaps it depends on the limitation of "a. "?
> >
> > 2) Often I encounter the necessity to replace element x by element y in an
> > array.
> > I solved the problem in an APL fashion such as:
> > repl=: 4 : '($y)$ (1{x) (((0{x)=,y)#i.*/$y)},y' NB. replace x1 in array y
> > by x2
> >
> > This verb works OK for any array, but I wonder if there is a better J-way
> > to do it.
> >
> > Thanks
> > Gian Medri
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
>
>
> ------------------------------
>
> Message: 5
> Date: Wed, 25 May 2011 16:42:28 +0800
> From: bill lam <[email protected]>
> Subject: Re: [Jprogramming] Sorting
> To: [email protected]
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset=utf-8
>
> You may try converting it to wide character first
>
> /:~ucp'qwe?rta?as?sdf'
> aadefqrsstw???
>
> or if you want utf8 back
>
> /:~&.ucp'qwe?rta?as?sdf'
> aadefqrsstw???
>
> if x is a rank-1 vector of 2 atom, I think it can be (untested)
>
> ($y) $ (1{x) (I.(0{x)=,y) } ,y
>
> please also refer to the verb charsub , that amend idiom should be supported
> by
> special code.
>
> ???, 25 ??? 2011, Gian Medri ?????(?):
> > Hi!
> > 1) I have a problem with sorting with the Swedish alphabet that contains 3
> > extra letters after z.
> > Example:
> > /:~'qwe?rta?as?sdf'
> > aadefqrsstw??????
> >
> > Perhaps it depends on the limitation of "a. "?
> >
> > 2) Often I encounter the necessity to replace element x by element y in an
> > array.
> > I solved the problem in an APL fashion such as:
> > repl=: 4 : '($y)$ (1{x) (((0{x)=,y)#i.*/$y)},y' NB. replace x1 in array y
> > by x2
> >
> > This verb works OK for any array, but I wonder if there is a better J-way
> > to do it.
> >
> > Thanks
> > Gian Medri
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
>
> --
> regards,
> ====================================================
> GPG key 1024D/4434BAB3 2008-08-24
> gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3
>
>
> ------------------------------
>
> Message: 6
> Date: Wed, 25 May 2011 11:11:14 +0200
> From: "R.E. Boss" <[email protected]>
> Subject: Re: [Jprogramming] Sorting
> To: "'Programming forum'" <[email protected]>
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset="UTF-8"
>
> rpl2a=: ] - (-/ , 0:)@[ {~ {.@[ i. ]
>
> by Hui from
> http://www.jsoftware.com/pipermail/programming/2007-July/007303.html is the
> most elegant known (to me).
>
> If x and y are from a small domain (e.g. characters), then rpl3a is faster
> and leaner:
> http://www.jsoftware.com/pipermail/programming/2007-July/007302.html
>
> rpl3a=: 4 : 0
> 'x0 x1'=. x
> ((x1,a.) {~ (x0,a.) i. ]) y
> )
>
>
> R.E. Boss
>
>
> > -----Oorspronkelijk bericht-----
> > Van: [email protected] [mailto:programming-
> > [email protected]] Namens Gian Medri
> (...)
>
> > 2) Often I encounter the necessity to replace element x by element y in an
> > array.
> > I solved the problem in an APL fashion such as:
> > repl=: 4 : '($y)$ (1{x) (((0{x)=,y)#i.*/$y)},y' NB. replace x1 in array y
> > by x2
> >
> > This verb works OK for any array, but I wonder if there is a better J-way
> > to do
> > it.
>
>
>
>
> ------------------------------
>
> Message: 7
> Date: Wed, 25 May 2011 18:50:57 +0800
> From: bill lam <[email protected]>
> Subject: Re: [Jprogramming] Sorting
> To: [email protected]
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset=utf-8
>
> What you see in jconsole or ide is _not_ the same as that inside J engine. For
> example, the character ? is one character in ide but it is two bytes in J
> engine, furthermore, J engine has no idea that these two bytes should be
> regarded as a single character, or know that you want them to be
> interpreted in utf8 encoding, or anything special. So nearly all string
> operations on these non-ascii characters will fail.
>
> There are some articles on unicodes in jwiki, please enter 'unicode' in the
> search box to locate them. They should provide some background materials.
>
> ???, 25 ??? 2011, Pablo Landherr ?????(?):
> > And I get
> >
> > 'qwe?rta?as?sdf'/:'abcdefghijklmnopqrstuvwxyz???' i. 'qwe?rta?as?sdf'
> > aadefqrsstw?
> > 9!:14 ''
> > j602/2008-03-03/16:45
> >
> > On Wed, May 25, 2011 at 10:00 AM, Gian Medri <[email protected]> wrote:
> >
> > > Hi!
> > > 1) I have a problem with sorting with the Swedish alphabet that contains 3
> > > extra letters after z.
> > > Example:
> > > /:~'qwe?rta?as?sdf'
> > > aadefqrsstw??????
> > >
> > > Perhaps it depends on the limitation of "a. "?
> > >
> > > 2) Often I encounter the necessity to replace element x by element y in an
> > > array.
> > > I solved the problem in an APL fashion such as:
> > > repl=: 4 : '($y)$ (1{x) (((0{x)=,y)#i.*/$y)},y' NB. replace x1 in array y
> > > by x2
> > >
> > > This verb works OK for any array, but I wonder if there is a better J-way
> > > to do it.
> > >
> > > Thanks
> > > Gian Medri
> > > ----------------------------------------------------------------------
> > > For information about J forums see http://www.jsoftware.com/forums.htm
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
>
> --
> regards,
> ====================================================
> GPG key 1024D/4434BAB3 2008-08-24
> gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3
>
>
> ------------------------------
>
> Message: 8
> Date: Wed, 25 May 2011 12:02:44 +0000
> From: "Dan Bron" <[email protected]>
> Subject: Re: [Jprogramming] J arrays
> To: "J Programming" <[email protected]>
> Message-ID:
> <1182149784-1306324965-cardhu_decombobulator_blackberry.rim.net-1490800668-@b18.c25.bise6.blackberry>
>
> Content-Type: text/plain
>
> Which is to say: exactly as much as your machine can handle (note the formula
> below also defines the limits of memory pointers on modern architectures).
>
> Which should also tell you that the max number of items depends on the size
> (in memory) of 1 item. The smallest J item is one byte (a literal atom), so
> you could have 4 billion of those on a 32 bit machine (modulo OS taxes). But
> if your items were, say, 4-byte integers, you'd max out at 1 billion. And if
> your items were tuples of 3 integers (R,G,B pixels, for example) you'd top
> out at ~300 million, etc.
>
>
> Of course, J also supports sparse arrays, which have the same theoretical
> limit (2^n etc) but much higher practical limits, as they only store the
> relevant parts of arrays (of course, if all the items of your array are
> relevant, you're back to the same memory limit).
>
> Why do you ask?
>
> -Dan
>
> PS: Roger's formula refers to the limit of a single dimension of a J array
> (the number of "items", as opposed to "atoms"). But J arrays are
> multidimensional, and each dimension could (in theory) have that many items,
> and of course the array's total volume is the product of all its dimensions.
> The max # of dimensions for a J array also shares Roger's limit, so the max
> shape J's internals can handle is
>
> shape =. $~ _1+2^n-1
>
> And correspondingly its volume would be */shape which is shape^shape or about
> 2^(n-1)^2 atoms. Which of course no machine can handle. But it does let you
> play silly games like carrying payload data around in the shape of an (empty)
> array :)
>
> And while we're discussing theory, it's worth pointing out that the
> specification of J (the Dictionary) imposes no limits on array size. So in
> theory, a different implementation of J could have arrays that stretched back
> onto disk (like a RDBMS), or across mutliple disks, or across multiple
> networked machines, or across the globe....
>
> The notation wouldn't change. Just the implementation.
>
>
>
> Please excuse typos; composed on a handheld device.
>
> -----Original Message-----
> From: Roger Hui <[email protected]>
> Sender: [email protected]
> Date: Tue, 24 May 2011 22:47:47
> To: Programming forum<[email protected]>
> Reply-To: Programming forum <[email protected]>
> Subject: Re: [Jprogramming] J arrays
>
> _1+2^n-1 where n is the number of bits in a machine word.
> (n is 32 or 64).
>
>
>
> ----- Original Message -----
> From: Charles Holder <[email protected]>
> Date: Tuesday, May 24, 2011 22:24
> Subject: [Jprogramming] J arrays
> To: [email protected]
>
> > What is the max items an array can have?
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
> ------------------------------
>
> Message: 9
> Date: Wed, 25 May 2011 10:22:03 -0400
> From: Devon McCormick <[email protected]>
> Subject: Re: [Jprogramming] Sorting
> To: Programming forum <[email protected]>
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset=UTF-8
>
> I like the boolean variant of replace:
>
> replace1by1=: 3 : 0
> 'toreplace replacement target'=. y
> (toreplace=target)}target,:replacement
> )
>
> replace1by1 'e';'X';'Replace one element by another'
> RXplacX onX XlXmXnt by anothXr
>
> $mat=. ><;._1 ' Replace one element by another'
> 5 7
>
> replace1by1 'e';'X';mat
> RXplacX
> onX
> XlXmXnt
> by
> anothXr
>
> On Wed, May 25, 2011 at 6:50 AM, bill lam <[email protected]> wrote:
>
> > What you see in jconsole or ide is _not_ the same as that inside J engine.
> > For
> > example, the character ? is one character in ide but it is two bytes in J
> > engine, furthermore, J engine has no idea that these two bytes should be
> > regarded as a single character, or know that you want them to be
> > interpreted in utf8 encoding, or anything special. So nearly all string
> > operations on these non-ascii characters will fail.
> >
> > There are some articles on unicodes in jwiki, please enter 'unicode' in the
> > search box to locate them. They should provide some background materials.
> >
> > ???, 25 ??? 2011, Pablo Landherr ?????(?):
> > > And I get
> > >
> > > 'qwe?rta?as?sdf'/:'abcdefghijklmnopqrstuvwxyz???' i. 'qwe?rta?as?sdf'
> > > aadefqrsstw?
> > > 9!:14 ''
> > > j602/2008-03-03/16:45
> > >
> > > On Wed, May 25, 2011 at 10:00 AM, Gian Medri <[email protected]>
> > wrote:
> > >
> > > > Hi!
> > > > 1) I have a problem with sorting with the Swedish alphabet that
> > contains 3
> > > > extra letters after z.
> > > > Example:
> > > > /:~'qwe?rta?as?sdf'
> > > > aadefqrsstw??????
> > > >
> > > > Perhaps it depends on the limitation of "a. "?
> > > >
> > > > 2) Often I encounter the necessity to replace element x by element y in
> > an
> > > > array.
> > > > I solved the problem in an APL fashion such as:
> > > > repl=: 4 : '($y)$ (1{x) (((0{x)=,y)#i.*/$y)},y' NB. replace x1 in
> > array y
> > > > by x2
> > > >
> > > > This verb works OK for any array, but I wonder if there is a better
> > J-way
> > > > to do it.
> > > >
> > > > Thanks
> > > > Gian Medri
> > > > ----------------------------------------------------------------------
> > > > For information about J forums see http://www.jsoftware.com/forums.htm
> > > ----------------------------------------------------------------------
> > > For information about J forums see http://www.jsoftware.com/forums.htm
> >
> > --
> > regards,
> > ====================================================
> > GPG key 1024D/4434BAB3 2008-08-24
> > gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
> >
>
>
>
> --
> Devon McCormick, CFA
> ^me^ at acm.
> org is my
> preferred e-mail
>
>
> ------------------------------
>
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
> End of Programming Digest, Vol 68, Issue 43
> *******************************************
----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm
