Symbols - that is what I had assumed, no right versions of floor/ceiling
(happily :)
Thanks for the Dyalog explanation - it is an indication of how removed
from APL I have drifted - try as I might, constructs like a[x;y;z]
didn't come to mind - interesting (I think). I was happily surprised
when the boxing went out, trough the forum, and back into my mail intact.
On 2013/07/02 15:33 , Roger Hui wrote:
With the other pages I could use APL symbols instead of ⌈ and
⌊, but there are no good alternatives to ⌉ and ⌋ (other
than the &#nnnn; or &#xnnnn; codes).
The tryapl.com page is not APL2 but Dyalog APL. In Dyalog APL ⍳vector is
similar to {i.&.>vector in J. (Note: in Dyalog APL and APL2 the enclose of
a simple scalar is the identity function, so the extension is compatible
with expressions like ⍳⍴x). It is a useful result for indexing and indexed
assignment.
Dyalog APL did not used to display arrays with the boxes when appropriate.
I have had a part in talking them (us!) into doing it.
On Tue, Jul 2, 2013 at 3:19 PM, Joey K Tuttle <[email protected]> wrote:
Touché ... but it is why I smile when I see the oft repeated assertion
that Unicode solves the problem of conveying APL (and other) symbols...
Other papers in
http://www.jsoftware.com/**papers/<http://www.jsoftware.com/papers/>(e.g.
Rational APL, Dictionary of APL, etc.) display correctly in all my
browsers, but I'm guessing you don't use ⌊ and ⌈ there...
Off the topic, but chat anyway - one of the pages that was up and looking
reasonable in the same Chrome instance was
http://tryapl.com/#
APL characters there seem to look reasonably OK (not perfect, but
recognizable). It seems like a nice little sandbox and I was poking at it
realizing that I felt like a Stranger in a Strange land when doing so...
That was an interesting feeling. I thought that maybe it was just the APL2
direction that had me off balance, but I looked at IBM APL2 reference
manual and saw nothing to explain/define the results of -
⍳2 3 4
┌→────┬─────┬─────┬─────┐
⍒1 1 1│1 1 2│1 1 3│1 1 4│
├~───→┼~───→┼~───→┼~───→┤
│1 2 1│1 2 2│1 2 3│1 2 4│
├~───→┼~───→┼~───→┼~───→┤
│1 3 1│1 3 2│1 3 3│1 3 4│
├~───→┼~───→┼~───→┼~───→┤
│2 1 1│2 1 2│2 1 3│2 1 4│
├~───→┼~───→┼~───→┼~───→┤
│2 2 1│2 2 2│2 2 3│2 2 4│
├~───→┼~───→┼~───→┼~───→┤
│2 3 1│2 3 2│2 3 3│2 3 4│
└~───→┴~───→┴~───→┴~───→┘
I couldn't guess or figure out anything I might use it for - there are
undoubtedly many other similar examples for someone using J for 25 years
and not much APL in that same period. Anyone have a nice explanation for
the difference from i.2 3 4 ?
On 2013/07/02 14:28 , Roger Hui wrote:
Symbols: Hey, that's not my department. :-) In the HTML source they were
entered as ⌈ ⌉ ⌊ and ⌋, and the way that are
rendered probably depends on what fonts are installed on your system.
I've
looked at them in my Chrome browser in Windows and on my Galaxy Tab and
they look fine.
On Tue, Jul 2, 2013 at 2:17 PM, Joey K Tuttle <[email protected]> wrote:
I don't have access to the 1968 edition, but would like to add that while
the link to APLQA.htm#Knuth renders OK in Firefox, the symbols are messed
up in Safari and Chrome on my iMac, but OK in both those browsers on my
iPad... Dunno why, just saying.
On 2013/07/02 13:39 , Eric Iverson wrote:
The quote (below as taken from your link) appears in the 1968 edition.
The notation [x] is often used elsewhere for one or the other of these
functions, usually the former; the notation above, which are due to
K.E. Iverson, are more useful, because both functions occur about
equally often in practice. The function ⌊x⌋ is sometimes called the
entier function, from the French word for “integer”.
There is a small difference. The 1968 edition has: "...the notations
above...". (note the s).
On Tue, Jul 2, 2013 at 4:26 PM, Roger Hui <[email protected]>
wrote:
http://www.jsoftware.com/****papers/APLQA.htm#Knuth<http://www.jsoftware.com/**papers/APLQA.htm#Knuth>
<http://**www.jsoftware.com/papers/**APLQA.htm#Knuth<http://www.jsoftware.com/papers/APLQA.htm#Knuth>
Does anyone have the original edition of Knuth's *The Art of Computer
Programming*, Volume 1, published in 1968? If so, can you please tell
me
whether the above quotation occurs in that edition?
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