thank you roger
I was struggling with how to match a graded representation back to the
original, that answered it:
]i /:~ i{vals [i=. \: vals [vals=.1 5 1 2 3 4
1 5 1 2 3 4
NB. strange way to determine if the value is the largest in the list, just
for illustration
i /:~ (=/{.) i{vals [i=. \: vals [vals=.1 5 1 2 3 4
0 1 0 0 0 0
vals=>./vals
0 1 0 0 0 0
the inverse permutation is what I was looking for
playing around with obverse
sortdownx =: 3 : 0
i=:\: y
i{y
)
invsortdownx =: 3 : 0
i /:~ y
)
sortdown =: sortdownx :. invsortdownx
]sortdown inv (=/{.) sortdown 5 1 3 6 4
0 0 0 1 0
sortdown2=: (3 : '[ i{y [ i=: \:y') :. (3 : 'i/:~y')
]sortdown2 inv (=/{.) sortdown2 5 1 3 6 4
0 0 0 1 0
NB. silly alternative
(causes,.> each(sortdown inv (+/\ % +/) sortdown vals)) -: (causes,.>each g
vals)
1
On Tue, Jun 3, 2014 at 10:41 AM, Roger Hui <[email protected]>
wrote:
> The treatment of an argument with duplicate entries obtain as follows:
>
> f =: 3 : 0
> sorted=: \:~ y
> vals =: (+/\ % +/) sorted
> (sorted i. y) { vals
> )
>
> g =: 3 : 0
> i /:~ (+/\ % +/) i{y [ i=. \:y
> )
>
> When the argument does not have duplicate entries, f and g are identical:
>
> (f -: g) 40?60
> 1
> (f -: g) 40?60
> 1
> (f -: g) 40?60
> 1
>
> But when there are duplicate entries:
>
> (f -: g) y=: 3 4 3 3 3
> 0
> f y
> 0.4375 0.25 0.4375 0.4375 0.4375
> g y
> 0.4375 0.25 0.625 0.8125 1
>
> g on the original y is seen to be "correct" when applied to a slightly
> perturbed y :
>
> y1=: y+1e_10*i.#y
> f y1
> 1 0.25 0.8125 0.625 0.4375
> g y1
> 1 0.25 0.8125 0.625 0.4375
>
> The difference between f and g is that g re-orders the cumulated ratios
> using the inverse permutation of i that sorted the argument. When y has no
> duplicates, the inverse permutation i is the same as (sorted i. y); in
> general, the inverse permutation is /:i. Note: i/:~blah ←→ blah/:i ←→
> (/:i){blah.
>
>
>
>
> On Tue, Jun 3, 2014 at 6:49 AM, Joe Bogner <[email protected]> wrote:
>
> > Thanks Pascal - good solution to my incorrect approach.
> >
> > Roger, I am using this with a pareto chart to identify what bin each
> record
> > would fall under.
> >
> > http://en.wikipedia.org/wiki/Pareto_chart
> >
> > I don't need to draw the chart, I just need to know what each record
> would
> > be classified as:
> >
> > causes =: > ' ' cut each LF cut(0 : 0)
> > Public 47
> > Weather 28
> > Oversight 18
> > Emergency 12
> > Traffic 5
> > ChildCare 57
> > )
> >
> > vals=. ". > 1}"1 causes
> >
> > runsumpct =: 3 : 0
> > sorted=. \:~ y
> > vals =. (+/\ % +/) sorted
> > (sorted i. y) { vals
> > )
> >
> > pct=:runsumpct vals
> > causes,.>each pct
> >
> > ┌─────────┬──┬────────┐
> > │Public │47│0.622754│
> > ├─────────┼──┼────────┤
> > │Weather │28│0.790419│
> > ├─────────┼──┼────────┤
> > │Oversight│18│0.898204│
> > ├─────────┼──┼────────┤
> > │Emergency│12│0.97006 │
> > ├─────────┼──┼────────┤
> > │Traffic │5 │1 │
> > ├─────────┼──┼────────┤
> > │ChildCare│57│0.341317│
> > └─────────┴──┴────────┘
> >
> > (/: pct) { (causes,.>each pct)
> >
> > ┌─────────┬──┬────────┐
> > │ChildCare│57│0.341317│
> > ├─────────┼──┼────────┤
> > │Public │47│0.622754│
> > ├─────────┼──┼────────┤
> > │Weather │28│0.790419│
> > ├─────────┼──┼────────┤
> > │Oversight│18│0.898204│
> > ├─────────┼──┼────────┤
> > │Emergency│12│0.97006 │
> > ├─────────┼──┼────────┤
> > │Traffic │5 │1 │
> > └─────────┴──┴────────┘
> >
> > I suppose I could sort the data before providing it to the function if
> that
> > helps.
> >
> > You are right that dupes cause problems with using i. to locate the
> record.
> > Thank you for pointing that out. I don't know how to fix it yet and would
> > welcome any suggestions.
> >
> > causes =: > ' ' cut each LF cut(0 : 0)
> > Public 47
> > Weather 28
> > Oversight 18
> > Emergency 12
> > Traffic 5
> > ChildCare 57
> > XYZ 5
> > )
> >
> >
> > (/: pct) { (causes,.>each pct)
> > ┌─────────┬──┬────────┐
> > │ChildCare│57│0.331395│
> > ├─────────┼──┼────────┤
> > │Public │47│0.604651│
> > ├─────────┼──┼────────┤
> > │Weather │28│0.767442│
> > ├─────────┼──┼────────┤
> > │Oversight│18│0.872093│
> > ├─────────┼──┼────────┤
> > │Emergency│12│0.94186 │
> > ├─────────┼──┼────────┤
> > │Traffic │5 │0.97093 │
> > ├─────────┼──┼────────┤
> > │XYZ │5 │0.97093 │
> > └─────────┴──┴────────┘
> >
> >
> >
> >
> > On Tue, Jun 3, 2014 at 9:10 AM, Roger Hui <[email protected]>
> > wrote:
> >
> > > y
> > > 1 100 5 10
> > > y,.runsumpct y
> > > 1 1
> > > 100 0.862069
> > > 5 0.991379
> > > 10 0.948276
> > >
> > > Please provide an English description of the problem being solved. In
> > > particular, I don't understand how the result is "in the original
> order".
> > > In addition, won't you have a problem if the argument has duplicate
> > > entries?
> > >
> > > t,.runsumpct t=: y,1 1 1
> > > 1 0.97479
> > > 100 0.840336
> > > 5 0.966387
> > > 10 0.92437
> > > 1 0.97479
> > > 1 0.97479
> > > 1 0.97479
> > >
> > >
> > >
> > >
> > >
> > > On Tue, Jun 3, 2014 at 4:32 AM, Joe Bogner <[email protected]>
> wrote:
> > >
> > > > Is there a cleaner way to write this or is this a reasonable
> > > > implementation?
> > > >
> > > > runsumpct =: 3 : 0
> > > >
> > > > sorted=: \:~ y
> > > >
> > > > vals =: (+/\ % +/) sorted
> > > >
> > > > (sorted i. y) { vals
> > > >
> > > > )
> > > >
> > > >
> > > > runsumpct 1 100 5 10
> > > >
> > > > 1 0.862069 0.991379 0.948276
> > > >
> > > >
> > > >
> > > > I'm interested if there's a cleaner approach to sorting, operating,
> and
> > > > then returning the result in the original order.
> > > >
> ----------------------------------------------------------------------
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> > > >
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