names =. (header i. <'nameFirst') {"1 data
frequency =. #/.~ names
names =. ~. names
(10 = frequency) # names
+-----+-----+-----+-----+-----+------+-----+------+--------+-------+
|Ruben|Paddy|Cecil|Chico|Edwin|Martin|Kelly|Junior|Jonathan|Duane|
+-----+-----+-----+-----+-----+------+-----+------+--------+-----+
On Tue, Oct 8, 2013 at 4:05 AM, Joe Bogner <[email protected]> wrote:
> I wrote:
> > Is there a better way to find indices of a subset within a greater list?
> This is my hacky solution
>
> Sorry, please disregard my question. I figured out a cleaner implementation
> using the table adverb
>
> (; > L:0 I. each <"1 (find =/ list)) { list
>
> NB. 13 : '(; > L:0 I. each <"1 (x =/ y)) { y'
> in=:] {~ [: ; [: >L:0 [: I.&.> [: <"1 =/
>
> ] find in list
>
> ┌─┬─┬─┬─┐
>
> │a│a│b│q│
>
> └─┴─┴─┴─┘
>
>
> ] (<'a') in ('a';'b')
>
> ┌─┐
>
> │a│
>
> └─┘
>
>
> ] ('a';'b') in ('a';'b';'c';'a')
>
> ┌─┬─┬─┐
>
> │a│a│b│
>
> └─┴─┴─┘
>
>
>
> idx=:13 : '(; > L:0 I. each <"1 (x =/ y))'
>
>
> Which then lets us do things like the following to merge/join tables
>
>
> (find idx list) { list
>
>
> My previous hack of namesTenRows=.(; L:0 > (3 : '(<y) ([: I. =) names' )
> each namesTen) { data
>
> Becomes: namesTenRows=. (namesTen idx names) { data
>
>
> Also quite a bit faster than the hacky solution
>
>
> ]1e5 * 1e5 (6!:2) '; > L:0 (3 : ''(<y) ([: I. =) list'' ) each find'
>
> 0.589178
>
>
> ]1e5 * 1e5 (6!:2) '(find idx list)'
>
> 0.224204
>
>
> Fun fun
>
>
> http://www.jsoftware.com/help/dictionary/d420.htm
> http://www.jsoftware.com/help/learning/18.htm
>
> I'd be happy to contribute to a wiki page on slicing/dicing tables. I don't
> have access to modify the wiki at present.
>
>
> On Tue, Oct 8, 2013 at 9:20 AM, Joe Bogner <[email protected]> wrote:
>
> > One more -- matching to a list (joining tables)
> >
> > NB. Get the names of everyone from the frequency table with exactly 10
> > matches
> >
> > ]namesTen=. > 0}"1 (10 ([: I. =) (> 1{"1 nameFrequency)) { nameFrequency
> >
> > ┌─────┬─────┬─────┬─────┬─────┬──────┬─────┬──────┬────────┬─────┐
> >
> > │Ruben│Paddy│Cecil│Chico│Edwin│Martin│Kelly│Junior│Jonathan│Duane│
> >
> > └─────┴─────┴─────┴─────┴─────┴──────┴─────┴──────┴────────┴─────┘
> >
> >
> >
> > namesTenRows=.(; L:0 > (3 : '(<y) ([: I. =) names' ) each namesTen) {
> data
> >
> >
> > NB. Get the unique names in our subset to validate it matches the above
> >
> > ] ~. (colIdx <'nameFirst') {"1 namesTenRows
> >
> > ┌─────┬─────┬─────┬─────┬─────┬──────┬─────┬──────┬────────┬─────┐
> >
> > │Ruben│Paddy│Cecil│Chico│Edwin│Martin│Kelly│Junior│Jonathan│Duane│
> >
> > └─────┴─────┴─────┴─────┴─────┴──────┴─────┴──────┴────────┴─────┘
> >
> >
> >
> > Is there a better way to find indices of a subset within a greater list?
> > This is my hacky solution
> >
> >
> > find=.('a';'b';'q')
> >
> > list=.('a';'b';'z';'c';'a';'q')
> >
> >
> > ] (; > L:0 (3 : '(<y) ([: I. =) list' ) each find) { list
> >
> > ┌─┬─┬─┬─┐
> >
> > │a│a│b│q│
> >
> > └─┴─┴─┴─┘
> >
> >
> > find xxx list
> >
> >
> >
> > On Tue, Oct 8, 2013 at 7:14 AM, Ric Sherlock <[email protected]> wrote:
> >
> >> A relatively simple adverb like the one below can be useful if you a
> >> repeatedly trying to access different fields in the table:
> >>
> >> NB.*getFields a Returns fields (columns) from y specified in x
> >>
> >> NB. EG: 'fieldname' tablehdr getFields table
> >>
> >> NB. EG: ('Lastname';'Firstname') hdr getFields dat
> >>
> >> NB. y is: table of records
> >>
> >> NB. m is: list of boxed field names in y
> >>
> >> NB. x is: list of boxed field names to return
> >>
> >> getFields=: 1 : 0
> >>
> >> :
> >>
> >> flds=. boxopen x
> >>
> >> idx=. m i. flds
> >>
> >> idx {"1 y
> >>
> >> )
> >>
> >>
> >> require 'tables/csv'
> >>
> >> 'hdr dat'=: split readcsv 'c:/tmp/master.csv'
> >>
> >>
> >> 4{. dat hdr getFields~ 'nameFirst';'birthYear';'weight'
> >>
> >>
> >> ┌──────┬────┬───┐
> >>
> >> │Hank │1934│180│
> >>
> >> ├──────┼────┼───┤
> >>
> >> │Tommie│1939│190│
> >>
> >> ├──────┼────┼───┤
> >>
> >> │Don │1954│190│
> >>
> >> ├──────┼────┼───┤
> >>
> >> │Andy │1972│184│
> >>
> >> └──────┴────┴───┘
> >>
> >>
> >>
> >>
> >> On Tue, Oct 8, 2013 at 11:39 PM, Joe Bogner <[email protected]>
> wrote:
> >>
> >> > Here are a couple other examples:
> >> >
> >> > NB. Convert years to a flat list of numbers
> >> >
> >> > birthYears=. , L:0 (> ". each ((colIdx <'birthYear') {"1 data))
> >> >
> >> >
> >> > NB. Find players born between 1930 and 1950 named Hank
> >> >
> >> > (I. (birthYears > 1930) * (birthYears < 1950) * (names = <'Hank')) {
> >> data
> >> >
> >> >
> >> > NB. Find players born between 1930 and 1950 named Hank or Tommie
> >> >
> >> > (I. (birthYears > 1930) * (birthYears < 1950) * ( (names = <'Hank') +
> >> > (names = <'Tommie'))) { data
> >> >
> >> >
> >> >
> >> > NB. http://www.jsoftware.com/jwiki/Essays/DataStructures
> >> >
> >> > diff=: -. [
> >> >
> >> > intersect=: e. # [
> >> >
> >> > union=: ~.@,
> >> >
> >> >
> >> > in=: ] ([: I. =)~ [: < [ NB. 4 : '(<x) ([: I.
> =)
> >> y'
> >> >
> >> > inT=: 4 : 'x in (colIdx <y) {"1 data'
> >> >
> >> >
> >> > NB. Another style
> >> >
> >> > NB. Hank or Tommie - the union of indices
> >> >
> >> > (('Hank' inT 'nameFirst') union ('Tommie' inT 'nameFirst')) { data
> >> >
> >> >
> >> > NB. Hank or Tommie AND born in Cuba
> >> >
> >> > ((('Hank' inT 'nameFirst') union ('Tommie' inT 'nameFirst')) intersect
> >> > ('Cuba' inT 'birthCountry')) { data
> >> >
> >> >
> >> >
> >> > On Tue, Oct 8, 2013 at 3:50 AM, R.E. Boss <[email protected]> wrote:
> >> >
> >> > > So 'data' was plural?
> >> > >
> >> > >
> >> > > R.E. Boss
> >> > >
> >> > > (Add your info to
> >> http://www.jsoftware.com/jwiki/Community/Demographics)
> >> > >
> >> > >
> >> > > > -----Original Message-----
> >> > > > From: [email protected] [mailto:
> programming-
> >> > > > [email protected]] On Behalf Of Henry Rich
> >> > > > Sent: dinsdag 8 oktober 2013 3:52
> >> > > > To: [email protected]
> >> > > > Subject: Re: [Jprogramming] Slicing and dicing tables
> >> > > >
> >> > > > That is what he meant, but it's a minority opinion.
> >> > > >
> >> > > > Henry Rich
> >> > > >
> >> > > > On 10/7/2013 8:56 PM, Dan Bron wrote:
> >> > > > > You mean " 'data' is plural " .
> >> > > > >
> >> > > > > -Dan
> >> > > > >
> >> > > > > PS: http://en.m.wikipedia.org/wiki/Muphry's_law
> >> > > > >
> >> > > > > (Yes, that link is spelled correctly :)
> >> > > > >
> >> > > > > Please excuse typos; composed on a handheld device.
> >> > > > >
> >> > > > > On Oct 7, 2013, at 8:00 PM, Eldon Eller <[email protected]>
> >> wrote:
> >> > > > >
> >> > > > >> Data are plural.
> >> > > > >>
> >> > > > >> On 10/07/2013 02:04 PM, Dan Bron wrote:
> >> > > > >>> Ganesh Rapolu
> >> > > > >>>> Because the data is boxed, all comparisons must be boxed.
> >> > > > >>> This was very well put (one short sentence which both
> clarifies
> >> the
> >> > > > >>> problem and justifies the solution).
> >> > > > >>>
> >> > > > >>> -Dan
> >> > > > >>>
> >> > > > >>>
> >> > > > >>>
> >> > > > >>>
> >> > --------------------------------------------------------------------
> >> > > > >>> -- For information about J forums see
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