On 10 December 2012 02:10, William Tanksley, Jr wtanksle...@gmail.com wrote:
Every notation has problems. If you don't see them, it's not because
they're not there. It's enormously ironic that you're denying ALL
problems with traditional notation
I am perfectly aware that every notation has
Numbers, too!
Linda
-Original Message-
From: programming-boun...@forums.jsoftware.com
[mailto:programming-boun...@forums.jsoftware.com] On Behalf Of David Ward
Lambert
Sent: Monday, December 10, 2012 9:32 AM
To: programming
Subject: Re: [Jprogramming] Just for fun, verb cross
cross=:
On Sun, Dec 9, 2012 at 5:01 PM, Boyko Bantchev boyk...@gmail.com wrote:
I also know many people who teach mathematics or informatics at
school, at different places and certainly to students with average
(or below) mathematical abilities. My wife has been a school teacher
in mathematics for
Changing the thread.
No. This is a way to check one's work in deriving a proof. And it is not
too difficult to convert the tacit expression to explicit then make the
proof. See example below. Interesting that you chose a monadic test. Tacit
verb phrases are ambivalent. Therefore there must be two
Yes... proofs are a topic that require some thought.
In J, I would usually do a proof as a sequence of statements that I
expect are all tautologies and where each sentence involves only a
minor changes from previous/next statements.
And, I would expect the reader to be verifying that they were
As for using J to teach students (presumably we're talking about elementary
to high-school level), I think my exposure to APL in junior high-school
(age 13) helped me better understand matrix math concepts when they were
introduced in high-school.
On Mon, Dec 10, 2012 at 10:21 AM, Raul Miller
1e308 ((+*-) -: (-*:)) 1e308
NaN error
1e308((+*-)-:(-*:))1e308
- Original Message -
From: Don Guinn dongu...@gmail.com
To: programm...@jsoftware.com
Sent: Monday, December 10, 2012 3:57 PM
Subject: Re: [Jprogramming] Proofs in J
Changing the thread.
No. This is a way to
You can convert to a single dyadic proof with (the well known, I'm
ensuring)
verb~~
From: Don Guinn dongu...@gmail.com
To: programm...@jsoftware.com
Subject: Re: [Jprogramming] Proofs in J
Message-ID:
CAEcakcOrEg48v=g98kdfagptu3cv0lucjw_xhemx-k9kpqd...@mail.gmail.com
If we are going to argue J v Python, we need to at least look at NumPy
(based in part on APL) and SciPy. If anybody is interested, I can
start those topics.
I also have another set of issues, regarding choice of languages in
working with Sugar education software. I will give the background
here,
That is lovely Arie,
It is that kind of elegance that I was chasing with my rougher attempts.
Using the (+.|.) hook simplifies (|.+.]) precisely and the { 0 1 combined
with ' ',. means that the selection of the string becomes a choice in each row
of displaying either the corresponding
The expression fails if the argument has duplicate items. e.g.
((+.|.)@={0 1 ' ',.)'aabbb'
|length error
| ((+.|.)@={0 1' ',.)'aabbb'
On Mon, Dec 10, 2012 at 10:18 AM, bob therriault bobtherria...@mac.comwrote:
That is lovely Arie,
It is that kind of elegance that I was chasing
I would be interested in NumPy.
I have to use python in some contexts, but I have not had the time to
study all the options, and on my own it would take me years to get up
to speed on something like NumPy.
As for the rest of your message: I will agree with you on the need for
a variety of
Here's a version that works with duplicated values (except note that
there was no specification for what the behavior should be in this
case):
(,@(#~01) (+.|.)@=)'abcde'
a e
b d
c
b d
a e
(,@(#~01) (+.|.)@=)'abcdedcba'
a e a
b d d b
c c
b d d b
a e a
--
Raul
On
Thanks for destroying my day.
Here's a much longer alternative
' ' (,{~[:((+.|.)@= ({0 1) 0,.) 1+i.@#@]) 'baabb'
b b
a a
a
b b
b b
_ (,{~ [: ((+.|.)@=({0 1) 0,.) 1+i.@#@]) 1 2 1 2
1 _ _ 1
_ 2 2 _
_ 1 1 _
2 _ _ 2
On 10-12-12 19:21, Roger Hui wrote:
The expression fails if the
Thanks Roger,
I guess this is why we race Ferrari's and go shopping in minivans. :)
My first draft survives repeats, but I still find Arie's version beautiful (and
functional within the specs of not having repeated items).
t0=:((.|.1)@(*=)@::@i.@#){ ' ',]
t0 'abcde'
a a
b b
c
d
Ugly as hell (but my J doesn't get any better without practicing):
cross =.(((1 {. 0 # ]), ]) {~ (:*(|.+.])@(=/~))@i.@#)
NB. Works for strings with replicated entries
cross 'aabbcdeabcde'
aa
b b
cc
d d
ee
aa
b b
cc
((+*-) -: (-*:))~ 10x^308
1
But mine goes to eleven:
((+*-) -: (-*:))~ 11x^308
1
On Mon, Dec 10, 2012 at 12:46 PM, Roger Stokes
r...@rogerstokes.free-online.co.uk wrote:
1e308 ((+*-) -: (-*:)) 1e308
NaN error
1e308((+*-)-:(-*:))1e308
- Original Message - From: Don
And, for what it's worth, here's a different plausible implementation
of cross (different only for the case of duplicated letters in the
argument when compared with the version I posted, below):
(,@(#~01) (+.|.)@=@(#\)) 'abcdedcba'
Note that replacing = with =@(#\) should also work for Aai's
Boyko, the discussion is futile whenyou do not believe that I am serious. But
note that the expression mc² has the dimension of energy. The expression
cm² (= 1cm²) has the dimension of area. Neither of these expressions evaluate
into a dimensionless number.
- Bo
My solution works by preparing a left argument for From { . It has rank two
solutions and is limited to string arguments.
cross
([: (+. |.1) [: (= * :) [: i. #) { ' ' , ]
cross 'a'
a a
a a
a
a a
a a
Kip Murray
Sent from my iPad
On Dec 10, 2012, at 1:48 PM, Raul
Without looking studying the sentence evaluator, I expected
+.|.@
(+. |.)@
to be identical to
+.(|.@)
|.@+.
Date: Mon, 10 Dec 2012 15:41:52 -0500
From: Raul Miller rauldmil...@gmail.com
To: programm...@jsoftware.com
Subject: Re: [Jprogramming] Just for fun, verb cross
Message-ID:
Yes...
The precedence rule for conjunctions is different when no right
argument is provided. In that case, the conjunction has lower
precedence than anything else in the language. It's as if there's a
free parenthesis to its left.
In other words
+.|.@
is equivalent to
(+. |.)@
The
On Mon, December 10, 2012 1:26 pm, Raul Miller wrote:
I would be interested in NumPy.
I have to use python in some contexts, but I have not had the time to
study all the options, and on my own it would take me years to get up
to speed on something like NumPy.
Start here.
Gripes:
The type system seems way too complex -- why should I care in the
typical case, what type of value is used to represent the numeric
value 1? Why can't it give me consistent operations? For example, I
do not like that booleans do not include the value 0 and 1 -- this not
only perpetuates
Is there a better way than the verb `am` to do the
following?
am =:_1 (I.@:-.@]})
am1] 2 6 ?.@$ 2
_1 _1 _1 _1 1 _1
_1 _1 _1 1 1 _1
(B=)
--
For information about J forums see http://www.jsoftware.com/forums.htm
Double the distance between 0 and 1, and then shift those points left one unit
on the number line.
am2=: ((-1) @ +:)
am21] 2 6 ?.@$ 2
_1 _1 _1 _1 1 _1
_1 _1 _1 1 1 _1
Does that make sense?
... peter
Brian Schott wrote:
Is there a better way than
:@:+: 0 1
_1 1
(_1 + +:)0 1 NB. for Linda
_1 1
Date: Mon, 10 Dec 2012 19:13:05 -0500 (EST)
From: Brian Schott schott.br...@gmail.com
To: programm...@jsoftware.com
Subject: [Jprogramming] convert 0,1 coding to _1,1
Message-ID: alpine.OSX.2.02.1212101905510.33557@server.local
Peter and David,
Thanks. That is a way that I had forgotten and may be preferred.
---
(B=)
On Dec 10, 2012, at 7:13 PM, Brian Schott schott.br...@gmail.com wrote:
Is there a better way than the verb `am` to do the following?
am =:_1 (I.@:-.@]})
am1] 2 6 ?.@$ 2
_1 _1 _1 _1 1 _1
_1 _1
My way would even work in Algebra I.
Linda
-Original Message-
From: programming-boun...@forums.jsoftware.com
[mailto:programming-boun...@forums.jsoftware.com] On Behalf Of David Ward
Lambert
Sent: Monday, December 10, 2012 7:58 PM
To: programming
Subject: Re: [Jprogramming] convert 0,1
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