You should show some dimensional information because many J operations
operate over a rank dimension (either default or explicit).
It looks like lineReactance is a matrix of 11 x 11, and phase is a vector
of 11?
Also, your problem statement doesn't match your examples:
Problem:
how to write a verb P(ij) = (phase(i) - phase(j))/lineReactance(ij)
and the examples:
((0{phase)-phase)% 0{lineReactance
The example doesn't appear to match the problem statement. Specifically
with the phrase:
phase(i) - phase(j)
vs
(0{phase) - phase
Those are two different operations. The first appears to be subtraction
between two numbers -- resulting in a scalar.
The latter appears to be extracting a scalar and subtracting a vector from
it, resulting in a vector (with scalar extension over the operator).
Perhaps you could clarify, and then the J programmers more savvy than I
might be better able to suggest a solution, other than the obvious, brute
force way of using two loops with i and j variables.
On Tue, May 21, 2013 at 9:49 AM, P T <[email protected]> wrote:
> I am almost close to finishing an initial version. But, I don't know how to
> write a verb P(ij) = (phase(i) - phase(j))/lineReactance(ij) where
>
>
> *lineReactance*
> 0 0.005 0.00625 0 0 0 0
> 0 0 0 0
> 0.005 0 0.04 0.00333333 0.01 0 0
> 0 0 0 0
> 0.00625 0.04 0 0 0 0 0 0.01
> 0.025 0 0
> 0 0.00333333 0 0 0.005 0.005 0.00333333
> 0 0 0 0
> 0 0.01 0 0.005 0 0 0.005
> 0 0 0 0
> 0 0 0 0.005 0 0 0.005
> 0 0 0 0.00666667
> 0 0 0 0.00333333 0.005 0.005 0
> 0 0 0 0.00833333
> 0 0 0.01 0 0 0 0 0
> 0.01 0.00625 0
> 0 0 0.025 0 0 0 0
> 0.01 0 0.02 0
> 0 0 0 0 0 0 0 0.00625
> 0.02 0 0.02
> 0 0 0 0 0 0.00666667 0.00833333
> 0 0 0.02 0
>
> *phase *
> 9.49428 5.92433 7.70672 4.02707 4.03065 2.58708 3.0874 5.96236 6.03134
> 4.82902 0
>
> I can compute one by one like
>
> ((0{phase)-phase)% 0{lineReactance
> 0 713.99 286.01 _ _ _ _ _ _ _ _
>
> ((1{phase)-phase)% 1{lineReactance
> _713.99 0 _44.5596 569.181 189.368 _ _ __ __ _ _
>
>
> But, how do I write this so that it computes for all items in the matrix?
>
> Thanks,
> PT
>
> How do I write a verb that computes
>
>
>
>
>
>
>
> On Tue, May 21, 2013 at 8:40 AM, Linda Alvord <[email protected]
> >wrote:
>
> >
> > odd=:2 & |
> > halve=:-:
> > veco =: 3 : '(c*1+3*y) + (halve y) * (1-c =. odd y)'
> > data =: 1 + i. 10000
> > veco3=:'((odd y)*1+3*y) + (halve y) * (1-odd y)'(13 : )
> > (veco3 data) -: (veco data)
> > 1
> >
> > veco3
> > (odd * 1 + 3 * ]) + halve * 1 - odd
> >
> > Linda
> >
> >
> > -----Original Message-----
> > From: [email protected]
> > [mailto:[email protected]] On Behalf Of Linda
> > Alvord
> > Sent: Tuesday, May 21, 2013 9:21 AM
> > To: [email protected]
> > Subject: Re: [Jprogramming] newbie help: how to avoid division by zero
> >
> > '(c*1+3*y) + (halve y) * (1-c =: odd y)'(13 : )
> > 3 : '(c*1+3*y) + (halve y) * (1-c =: odd y)'
> > '(c*1+3*y) + (halve y) * (1-c =. odd y)'(13 : ) halve (* + [ * 1 - ])
> > odd
> >
> > Linda
> >
> > -----Original Message-----
> > From: [email protected]
> > [mailto:[email protected]] On Behalf Of Linda
> > Alvord
> > Sent: Tuesday, May 21, 2013 7:13 AM
> > To: [email protected]
> > Subject: Re: [Jprogramming] newbie help: how to avoid division by zero
> >
> > I didn't realize that this definition for veco2 did not work.
> >
> > data =: 1 + i. 10000
> > veco =: 3 : '(c*1+3*y) + (halve y) * (1-c =. odd y)'
> > '(c*1+3*y) + (halve y) * (1-c =. odd y)'(13 : ) halve (* + [ * 1 - ])
> > odd
> > veco2=:halve (* + [ * 1 - ]) odd
> > (veco2 data) -: (veco data)
> > 0
> >
> > So, although your substitution works, it doesn't help.
> >
> > veco3=:halve (* -.) odd
> > (veco3 data) -: (veco data)
> >
> > I'll be more careful about testing the results of: ' '(13 : )
> >
> > Linda
> >
> >
> > -----Original Message-----
> > From: [email protected]
> > [mailto:[email protected]] On Behalf Of David
> Ward
> > Lambert
> > Sent: Monday, May 20, 2013 12:24 PM
> > To: programming
> > Subject: Re: [Jprogramming] newbie help: how to avoid division by zero
> >
> > I'd replace ([ * 1 - ]) with (* -.) .
> > As previously observed, 13 :'quoted expression' won't write hooks.
> >
> > (([ * 1 - ]) -: (* -.)) -:i:8 NB. monad
> > 1
> > (([ * 1 - ])/ -: (* -.)/)~ -:i:8 NB. dyad
> > 1
> >
> > >Date: Sun, 19 May 2013 11:43:52 -0400
> > >From: "Linda Alvord" <[email protected]>
> > >To: <[email protected]>
> > >Subject: Re: [Jprogramming] newbie help: how to avoid division by zero
> > >Message-ID: <000101ce54a7$aa2d4c10$fe87e430$@net>
> > >Content-Type: text/plain; charset=US-ASCII
> > >
> > > It is worth noting further simplification by J:
> > >
> > > veco=: 13 :'(c*1+3*y) + (halve y) * (1-c =. odd y)'
> > > veco
> > >halve (* + [ * 1 - ]) odd
> > >
> > >Linda
> >
> >
> > ----------------------------------------------------------------------
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> >
> > ----------------------------------------------------------------------
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> >
> > ----------------------------------------------------------------------
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> >
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> >
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>
--
Best regards,
Alan
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