The difference is that a is an empty nested array and that b is an
empty simple array. The depths would be different. I tried this
example on Dyalog and ≡a is 2, one level of nesting, while ≡b is 1, a
simple vector.
Also see http://www.sudleyplace.com/APL/Prototype%20Functions.pdf
On 1/29/14, E
I would try to import the matrix in pieces. Try something like
mat←951192 10⍴ '' '' '' '' '' '' '' '' 0 0
then import the columns separately, i.e.
mat[;1]←(↓col1)~¨' '
mat[;2]←(↓col2)~¨' '
where col1, col2, and friends are simple character matrices containing
data for those c
Function definition mode (typing ∇ followed by a symbol name) is an
artifact of the kind of terminal hardware supported by APL (the IBM
2741 with its iconic typeballs) in the 1960s. As such, nearly 50
years later, it may be worth rethinking some of these things to take
advantage of newer editor a
The / and \ symbols (and their first coordinate versions ⌿ and ⍀) were
overloaded from the start. Not enough characters on the 2741 typeball
or something. Symbol pressure.
First, they are the compression and expansion functions.
1 0 1 / 1 2 3
Second, they are the reduction and scan operators.
+/1
As for file systems, I did something like this years ago for a client
who (A) refused to have his data tied up in a proprietary format, and
(B) wanted to share data across Dyalog APL and APL2000. This dates
back to the Windows 8.3 FAT file system days, this could be far better
(or worse) with the
Have a look at IBM's AP127 documentation
http://www-01.ibm.com/software/awdtools/apl/library.html
See APL2 Programming: Using Structured Query Language (PDF)
SH21-1057-07, it's the 4th from the bottom.
I wouldn't recommend building anything like this today, but it would
be possibly instructive t
Just an idea. Has anyone any experience with some of the input method
editors for Asian languages, notably Japanese? I think I have seen
something where you would type ordinary Roman letters and the input
handler would translate them first to Hiragana or Katakana (parallel
phonetic alphabets), th
Back in the mainframe days, branching style was a big deal. almost
religion, as some forms were slightly faster than others. The
following were the standard branch and were all interchangeable,
except that maybe rho was faster than slash or something.
→(I=M) / L270
→(I=M) ⍴ L270
→(I=M) ↑ L270
Al
Generally every APL vendor added extra features into their version of
the language, sometimes to accommodate new hardware or environments,
sometimes to enhance their competitive advantage.
Burroughs and one or another DEC APL used cute quad-something glyphs,
mostly for their file system operations
Before the parsing comes the lexical analysis
Have a look at the ancient Unix lex (or flex) utility for some insight
as to how GNU APL might recognise numbers. Also, have a look at the
APL.LEX definition file from Timothy Budd's APLc compiler project,
see http://home.earthlink.net/~swsirlin/a
I use the following idiom for string insertion. It works reasonably
well when the integer width is small, 1 or 2 bytes.
But first, let's change the problem slightly get rid of the "e", then
insert "www" after the "l" in "alx". This solution is for origin 1.
a←'alx'
b←'www'
(a,
Something is missing here, most probably a relational function
[2] L1:→((⍴B)P←B⍳1)/L2
probably should be more like
[2] L1:→((⍴B) < P←B⍳1)/L2
Another place where there is some APL message traffic is
stackoverflow.com. Look for the APL tag. You will need to enroll.
Although this site is very much social media and its motives are, as
usual, not entirely clear, it is a great source for answers in many
different computer languages and tec
There is at least one other degenerate case, namely the "legacy"
singleton, or one element vector. With a scalar argument, monadic
iota returns a result depth one. With a vector argument, iota returns
a result depth two. Except when there is only one element.
≡⍳⍳0 ⍝ can't find zilde
2
Wouldn't this really be a domain error, the maximum argument value for
! being around 170?
!170
7.257415615307994E306
!171
DOMAIN ERROR
!171
(example on dyalog)
On 12/16/16, Kacper Gutowski wrote:
> Hello,
> Binomial returns malformed result when called with some non-integer
>
Interesting. On Dyalog, the domain of 0!x are the small integers
-32768 to 32767.
Elias,
In just about any language, iterative string catenation is a real
performance killer owing to the repeated growing memory allocation
which just gets bigger with every iteration.
I would restructure the algorithm to work more like this: (sorry, on
a Windoze box and no APL, so metacode only
The key to understanding inner product is that the inner dimensions of
the arguments have to be the same. The inner dimension here is 3.
a←2 3⍴⍳6
b←3 4⍴⍳12
a
0 1 2
3 4 5
b
0 1 2 3
4 5 6 7
8 9 10 11
a+.×b
20 23 26 29
56 68 80 92
To solve this, first transpose th
Thank you.
Forgot to mention scalar extension. When a scalar is supplied as an
argument, it's lengthened to match the inner dimension of the other
argument.
(3 4⍴'cattrattfatt') +.= 't'
2 2 2
(3 4⍴'cattrattfatt') +.= ''
2 2 2
'a' +.= 3 4⍴'catratfatbat'
1 1 1 1
'aaa' +.
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