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math.statistics: make collect-by row polymorphic, simplify words.

db4
John Benediktsson 2013-04-22 06:25:50 -07:00
parent 8574b25a96
commit 35e23dc547
2 changed files with 12 additions and 15 deletions
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4
basis/math/statistics/statistics-docs.factor
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@ -238,7 +238,7 @@ HELP: rescale
HELP: collect-by
{ $values
{ "seq" sequence } { "quot" { $quotation "( obj -- ? )" } }
{ "seq" sequence } { "quot" { $quotation "( ... obj -- ... key )" } }
{ "hashtable" hashtable }
}
{ $description "Applies a quotation to each element in the input sequence and returns a " { $snippet "hashtable" } " of like elements. The keys of this " { $snippet "hashtable" } " are the output of " { $snippet "quot" } " and the values at each key are the elements that transformed to that key." }
@ -254,7 +254,7 @@ HELP: collect-by
HELP: collect-index-by
{ $values
{ "seq" sequence } { "quot" { $quotation "( obj -- ? )" } }
{ "seq" sequence } { "quot" { $quotation "( ... obj -- ... key )" } }
{ "hashtable" hashtable }
}
{ $description "Applies a quotation to each element in the input sequence and returns a " { $snippet "hashtable" } " of like elements. The keys of this " { $snippet "hashtable" } " are the output of " { $snippet "quot" } " and the values at each key are the indices for the elements that transformed to that key." }

23
basis/math/statistics/statistics.factor
View File

@ -247,18 +247,17 @@ PRIVATE>
: normalized-histogram ( seq -- alist )
[ histogram ] [ length ] bi '[ _ / ] assoc-map ;
: collect-index-by ( seq quot -- hashtable )
[ swap ] prepose [ push-at ] sequence-index>hashtable ; inline
: collect-index-by ( ... seq quot: ( ... obj -- ... key ) -- ... hashtable )
[ dip swap ] curry [ push-at ] sequence-index>hashtable ; inline
: collect-by ( seq quot -- hashtable )
[ dup ] prepose [ push-at ] sequence>hashtable ; inline
: collect-by ( ... seq quot: ( ... obj -- ... key ) -- ... hashtable )
[ keep swap ] curry [ push-at ] sequence>hashtable ; inline
: equal-probabilities ( n -- array )
dup recip <array> ; inline
: mode ( seq -- x )
histogram >alist
[ ] [ [ [ second ] bi@ > ] most ] map-reduce first ;
histogram >alist [ second ] supremum-by first ;
: minmax ( seq -- min max )
[ first dup ] keep [ [ min ] [ max ] bi-curry bi* ] each ;
@ -380,18 +379,16 @@ ALIAS: std sample-std
flip [ standardize ] map flip ;
: differences ( u -- v )
[ 1 tail-slice ] keep v- ;
[ rest-slice ] keep v- ;
: rescale ( u -- v )
dup minmax over - [ v-n ] [ v/n ] bi* ;
: rankings ( histogram -- assoc )
sort-keys 0 swap [ rot [ + ] keep swapd ] H{ } assoc-map-as nip ;
: rank-values ( seq -- seq' )
[
[ ] [ length iota ] bi zip sort-keys
[ [ first ] bi@ = ] monotonic-split
[ values ] map [ 0 [ length + ] accumulate nip ] [ ] bi zip
] [ length f <array> ] bi
[ '[ first2 [ _ set-nth ] with each ] each ] keep ;
dup histogram rankings '[ _ at ] map ;
: z-score ( seq -- n )
[ demean ] [ sample-std ] bi v/n ;