Sorry, the first line below was cropped, the first character should have been; >
as in “>./~ i.5” It is clearer in the second line included. …/Rob > On 15 May 2018, at 11:34 pm, Rob Hodgkinson <[email protected]> wrote: > > Jimmy, a further note (this does not reproduce your actual diagram, but does > present a J algorithm to produce the square matrix of same pattern as your > diagram … > >> ./~ i.5 > 0 1 2 3 4 > 1 1 2 3 4 > 2 2 2 3 4 > 3 3 3 3 4 > 4 4 4 4 4 > |. '.oO*&' {~ >./~ i.5 > &&&&& > ****& > OOO*& > ooO*& > .oO*& > > Rob > >> On 15 May 2018, at 9:21 am, Raul Miller <[email protected]> wrote: >> >> Are you looking for something like this for "figure 2.1"? >> >> o=: _1 1 }. ":@<@(,~ 'o ' $~ {:@$)@(,. ' o' $~ #) >> o o o o _1 1 }.":<'o' >> ─────────┐ >> o o o o o│ >> ───────┐ │ >> o o o o│o│ >> ─────┐ │ │ >> o o o│o│o│ >> ───┐ │ │ │ >> o o│o│o│o│ >> ─┐ │ │ │ │ >> o│o│o│o│o│ >> >> Thanks, >> >> -- >> Raul >> >> On Tue, May 15, 2018 at 9:42 AM, Jimmy Gauvin <[email protected]> wrote: >>> Hi all, >>> >>> In "Makers of Mathematics" by Stuart Hollingdale there is a reference about >>> Pythagoreans who where in the habit of representing numbers by pebbles in >>> the sand. >>> >>> Figure 2.1 illustrates how square numbers can be generated by adding >>> successive odd numbers. >>> >>> ───────┐ >>> o o o o│ >>> ─────┐ │ >>> o o o│o│ >>> ───┐ │ │ >>> o o│o│o│ >>> ─┐ │ │ │ >>> o│o│o│o│ >>> >>> >>> The sum of first n odd numbers is simply n^2. >>> >>> How about some J code to generate figure 2.1 ? >>> >>> >>> >>> >>> >>> On Tue, May 15, 2018 at 5:22 AM, 'Jon Hough' via Programming < >>> [email protected]> wrote: >>> >>>> Try this: >>>> >>>> smodd1=:+/@:>:@:+:@:i. >>>> >>>> Your tacit verb was creating forks, as can be seen with dissect: >>>> load 'debug/dissect' >>>> dissect '+/1+2*i. 5' >>>> >>>> >>>> But since the sum of the first N odd numbers is N^2 >>>> it is easiest to write >>>> smodd=: *: >>>> >>>> >>>> -------------------------------------------- >>>> On Tue, 5/15/18, Skip Cave <[email protected]> wrote: >>>> >>>> Subject: [Jprogramming] Summing odd numbers >>>> To: "[email protected]" <[email protected]> >>>> Date: Tuesday, May 15, 2018, 5:29 PM >>>> >>>> A simple Quora question wants to know the >>>> formula to sum the first n odd >>>> numbers. >>>> >>>> I can write an explicit verb: >>>> >>>> smodd =.3 :'+/1+2*i.y' >>>> >>>> smodd 5 >>>> >>>> 25 >>>> >>>> I want to write a tacit verb: >>>> >>>> smodd1=:+/1+2*i. >>>> >>>> smodd1 5 >>>> >>>> 6 8 10 12 14 >>>> >>>> What am I doing wrong? >>>> >>>> >>>> Skip Cave >>>> Cave Consulting LLC >>>> ---------------------------------------------------------------------- >>>> For information about J forums see http://www.jsoftware.com/forums.htm >>>> ---------------------------------------------------------------------- >>>> For information about J forums see http://www.jsoftware.com/forums.htm >>>> >>> ---------------------------------------------------------------------- >>> For information about J forums see http://www.jsoftware.com/forums.htm >> ---------------------------------------------------------------------- >> For information about J forums see http://www.jsoftware.com/forums.htm > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
