Hi Stefan Scott,
I am enjoying your explorations. I haven't had time really dig in, but the
(i. 6);(i. 6);(i. 6)
could be replaced by
3 # < i. 6
I await those with more experience to shower us with elegance.
Cheers, bob
ps. If you subscribe to chat, we'd love your input on some of the animations
we've been building to assist new J'ers. bt
On -Mar13-2010, at -Mar13-20108:32 PM, Stefan Scott Alexx wrote:
> I just now realized that (as often seems to happen with J) there are at
> least two other ways to compute all combinations of 3 (or x) elements from a
> set of six (or y) elements. (This computation was used in my previous post
> "A viewmat phrase to display all 216 web-safe colors" to compute argument x
> to dyad viewmat.)
>
> So instead of the phrase provided in the previous post for displaying 216
> web-safe colors:
>
> (51 * (6 (&#.)(^:_1) i. 216)) viewmat 12 18 i. 216
>
> Either of the two following equivalent (possibly simpler) phrases could also
> be used, the first using "Antibase" ( #: ) and the second using "Catalogue"
> or "Cartesian Product" ( } ):
>
> (51 * 6 6 6 #: i. 216) viewmat 12 18 $ i. 216
>
> (51 * > , { (i. 6);(i. 6);(i. 6)) viewmat 12 18 $ i. 216
>
> +++
>
> That previous post computed the base x representation of decimal number
> using the dyad:
>
> (&#.)(^:_1)
>
> defined here:
>
> http://www.jsoftware.com/help/phrases/representations.htm
>
> For example, the previous post computed the base 6 representation of the
> numbers from 0 to 215 as follows:
>
> 6 (&#.)(^:_1) i. 216
>
> However, I now see there are a couple of (possibly simpler) alternative
> phrases.
>
> +++
>
> (1) One alternative uses "Unbox" on "Enfile" on "Catalogue" or "Cartesian
> Product":
>
>> , { (i. 6);(i. 6);(i. 6)
>
> "Catalog" and "Cartesian Product" are defined here:
>
> http://www.jsoftware.com/help/dictionary/d520.htm
>
>
> As a side note - I am curious if there is a more compact way of representing
> the repetitive phrase:
>
> (i. 6);(i. 6);(i. 6)
>
> I have tried fiddling with tacking combinations of the adverbs ~ and / and
> ^:3 onto the verb ; ... but no luck.
>
> +++
>
> (2) Another alternative uses "Antibase":
>
> 6 6 6 #: i. 216
>
> defined here:
>
> PDF!
> http://www.jsoftware.com/jwiki/HenryRich?action=AttachFile&do=get&target=J602_RefCard_color_letter_current.pdf
>
> +++
>
> Upon first reading, it wasn't clear to me from the definition of dyad
> Antibase provided in the Vocabulary here:
>
> http://www.jsoftware.com/help/dictionary/d402.htm
>
> that its x argument could be an integer array each of whose elements is the
> desired base. But the example for "Antibase" in the above PDF from Henry
> Rich made it clear how to do this.
>
> +++ +++ +++
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