Use the phrases =y and =/~y with care. For example, try it when y has duplicate elements:
y=: 3 1 4 1 5 9 =y 1 0 0 0 0 0 0 1 0 1 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 =/~y 1 0 0 0 0 0 0 1 0 1 0 0 0 0 1 0 0 0 0 1 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 On Mon, Nov 19, 2012 at 9:22 PM, Don & Cathy Kelly <d...@shaw.ca> wrote: > That should be in the phrases rather than what I used! > Ric's definition also works but not with a 5 element list > y=:2 3 6 8 9 > = y > 1 0 0 0 0 > 0 1 0 0 0 > 0 0 1 0 0 > 0 0 0 1 0 > 0 0 0 0 1 > =/~y > 1 0 0 0 0 > 0 1 0 0 0 > 0 0 1 0 0 > 0 0 0 1 0 > 0 0 0 0 1 > > Thank you both - so many ways to skin a cat! > > Don > On 19/11/2012 9:01 PM, Bo Jacoby wrote: > >> The unit matrix is >> =/~i.5 >> 1 0 0 0 0 >> 0 1 0 0 0 >> 0 0 1 0 0 >> 0 0 0 1 0 >> 0 0 0 0 1 >> >> - Bo >> >> >> >> >> >> ______________________________**__ >>> Fra: Don & Cathy Kelly <d...@shaw.ca> >>> Til: programm...@jsoftware.com >>> Sendt: 0:47 tirsdag den 20. november 2012 >>> Emne: Re: [Jprogramming] Verb definition + inadvertent train formation. >>> >>> No - I should have made it clear that the actual y is a list of n >>> numbers and I need to add this list to the diagonal of a matrix. >>> Since this will (of necessity) be within a loop and each time both the >>> list and matrix will be modified (except for size), >>> I have come to the conclusion that I should make a single unit matrix >>> outside the iteration and use this each time. >>> ] u=:=@i.@#i.5 >>> >>> 1 0 0 0 0 >>> 0 1 0 0 0 >>> 0 0 1 0 0 >>> 0 0 0 1 0 >>> 0 0 0 0 1 >>> >>> y=: 2 3 5 4 10 >>> >>> ]u *y >>> 2 0 0 0 0 >>> 0 3 0 0 0 >>> 0 0 5 0 0 >>> 0 0 0 4 0 >>> 0 0 0 0 10 >>> repeating with different y values as needed. >>> >>> The algorithm for u is taken from the "phrases" section of the >>> vocabulary-maybe you have a simpler one?- >>> Thanks >>> >>> Don >>> >>> >>> On 18/11/2012 10:33 PM, bob therriault wrote: >>> >>>> Hi Don, >>>> >>>> Are you looking for >>>> >>>> y=:5 >>>> c=:(*=)&i. >>>> c y >>>> 0 0 0 0 0 >>>> 0 1 0 0 0 >>>> 0 0 2 0 0 >>>> 0 0 0 3 0 >>>> 0 0 0 0 4 >>>> Cheers, bob >>>> >>>> On 2012-11-18, at 7:13 PM, Don & Cathy Kelly wrote: >>>> >>>> OOPs' I meant y=:i.5 5 >>>>> >>>>> Don >>>>> On 18/11/2012 7:04 PM, Don & Cathy Kelly wrote: >>>>> >>>>>> That gives the diagonal nicely but the problem that I didn't express >>>>>> clearly is that I want a matrix as follows >>>>>> y=:i.5 >>>>>> >>>>>> ]result =: (* =@i.@#) y >>>>>> 0 0 0 0 0 >>>>>> 0 1 0 0 0 >>>>>> 0 0 2 0 0 >>>>>> 0 0 0 3 0 >>>>>> 0 0 0 0 4 >>>>>> which II can get by >>>>>> c=:* =@i.@# >>>>>> c y >>>>>> 0 0 0 0 0 >>>>>> 0 1 0 0 0 >>>>>> 0 0 2 0 0 >>>>>> 0 0 0 3 0 >>>>>> 0 0 0 0 4 >>>>>> >>>>>> For my purposes I can use a base nth order unit matrix by the phrase >>>>>> as given in phrases as m=:=@i.@# y >>>>>> and then deal with m* y1 , m* y2 etc which suits my purpose which is >>>>>> to form a specific Jacobean used for power system load flows. >>>>>> I have handled this problem in APL and am trying to replicate the >>>>>> coding more directly in J-mainly as an exploration of J for my own >>>>>> satisfaction. >>>>>> >>>>>> Thank you >>>>>> >>>>>> Don Kelly >>>>>> >>>>> ------------------------------**------------------------------** >>>> ---------- >>>> For information about J forums see http://www.jsoftware.com/** >>>> forums.htm <http://www.jsoftware.com/forums.htm> >>>> >>>> ------------------------------**------------------------------** >>> ---------- >>> For information about J forums see >>> http://www.jsoftware.com/**forums.htm<http://www.jsoftware.com/forums.htm> >>> >>> >>> >>> ------------------------------**------------------------------** >> ---------- >> For information about J forums see >> http://www.jsoftware.com/**forums.htm<http://www.jsoftware.com/forums.htm> >> >> > ------------------------------**------------------------------**---------- > For information about J forums see > http://www.jsoftware.com/**forums.htm<http://www.jsoftware.com/forums.htm> > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
