add finance words to math.finance

extra/math/finance/finance-docs.factor

@@ -32,3 +32,44 @@ HELP: momentum
     { $list "MOM[t] = SEQ[t] - SEQ[t-n]" }
 } ;
 
+HELP: biweekly
+{ $values
+     { "x" number }
+     { "y" number }
+}
+{ $description "Divides a number by the number of two week periods in a year." } ;
+
+HELP: daily-360
+{ $values
+     { "x" number }
+     { "y" number }
+}
+{ $description "Divides a number by the number of days in a 360-day year." } ;
+
+HELP: daily-365
+{ $values
+     { "x" number }
+     { "y" number }
+}
+{ $description "Divides a number by the number of days in a 365-day year." } ;
+
+HELP: monthly
+{ $values
+     { "x" number }
+     { "y" number }
+}
+{ $description "Divides a number by the number of months in a year." } ;
+
+HELP: semimonthly
+{ $values
+     { "x" number }
+     { "y" number }
+}
+{ $description "Divides a number by the number of half-months in a year. Note that biweekly has two more periods than semimonthly." } ;
+
+HELP: weekly
+{ $values
+     { "x" number }
+     { "y" number }
+}
+{ $description "Divides a number by the number of weeks in a year." } ;

extra/math/finance/finance.factor

@@ -26,3 +26,14 @@ PRIVATE>
 : momentum ( seq n -- newseq )
     [ tail-slice ] 2keep [ dup length ] dip - head-slice v- ;
 
+: monthly ( x -- y ) 12 / ; inline
+
+: semimonthly ( x -- y ) 24 / ; inline
+
+: biweekly ( x -- y ) 26 / ; inline
+
+: weekly ( x -- y ) 52 / ; inline
+
+: daily-360 ( x -- y ) 360 / ; inline
+
+: daily-365 ( x -- y ) 365 / ; inline