Rename count-factors to group-factors and update docs

db4
Aaron Schaefer 2008-01-14 11:33:08 -05:00
parent 75774188ea
commit 8bc631f5ed
4 changed files with 17 additions and 14 deletions

View File

@ -1,20 +1,23 @@
USING: help.markup help.syntax ;
USING: help.markup help.syntax math sequences ;
IN: math.primes.factors
{ factors count-factors unique-factors } related-words
{ factors group-factors unique-factors } related-words
HELP: factors
{ $values { "n" "a positive integer" } { "seq" "a sequence" } }
{ $description { "Factorize an integer and return an ordered list of factors, possibly repeated." } } ;
{ $values { "n" "a positive integer" } { "seq" sequence } }
{ $description { "Return an ordered list of a number's prime factors, possibly repeated." } }
{ $examples { $example "300 factors ." "{ 2 2 3 5 5 }" } } ;
HELP: count-factors
{ $values { "n" "a positive integer" } { "seq" "a sequence" } }
{ $description { "Return a sequence of pairs representing each factor in the number and its corresponding power." } } ;
HELP: group-factors
{ $values { "n" "a positive integer" } { "seq" sequence } }
{ $description { "Return a sequence of pairs representing each prime factor in the number and its corresponding power (multiplicity)." } }
{ $examples { $example "300 group-factors ." "{ { 2 2 } { 3 1 } { 5 2 } }" } } ;
HELP: unique-factors
{ $values { "n" "a positive integer" } { "seq" "a sequence" } }
{ $description { "Return an ordered list of unique prime factors." } } ;
{ $values { "n" "a positive integer" } { "seq" sequence } }
{ $description { "Return an ordered list of a number's unique prime factors." } }
{ $examples { $example "300 unique-factors ." "{ 2 3 5 }" } } ;
HELP: totient
{ $values { "n" "a positive integer" } { "t" "an integer" } }
{ $description { "Return the number of integers between 1 and " { $snippet "n-1" } " relatively prime to " { $snippet "n" } "." } } ;
{ $values { "n" "a positive integer" } { "t" integer } }
{ $description { "Return the number of integers between 1 and " { $snippet "n-1" } " that are relatively prime to " { $snippet "n" } "." } } ;

View File

@ -1,6 +1,6 @@
USING: math.primes.factors tools.test ;
{ { 999983 999983 1000003 } } [ 999969000187000867 factors ] unit-test
{ { { 999983 2 } { 1000003 1 } } } [ 999969000187000867 count-factors ] unit-test
{ { { 999983 2 } { 1000003 1 } } } [ 999969000187000867 group-factors ] unit-test
{ { 999983 1000003 } } [ 999969000187000867 unique-factors ] unit-test
{ 999967000236000612 } [ 999969000187000867 totient ] unit-test

View File

@ -27,7 +27,7 @@ PRIVATE>
: factors ( n -- seq )
[ (factor) ] (decompose) ; foldable
: count-factors ( n -- seq )
: group-factors ( n -- seq )
[ (count) ] (decompose) ; foldable
: unique-factors ( n -- seq )

View File

@ -88,7 +88,7 @@ PRIVATE>
! The divisor function, counts the number of divisors
: tau ( m -- n )
count-factors flip second 1 [ 1+ * ] reduce ;
group-factors flip second 1 [ 1+ * ] reduce ;
! Optimized brute-force, is often faster than prime factorization
: tau* ( m -- n )