RosettaCodeData/Task/Fractran/REXX/fractran-1.rexx
2019-09-12 10:33:56 -07:00

24 lines
2 KiB
Rexx

/*REXX program runs FRACTRAN for a given set of fractions and from a specified N. */
numeric digits 2000 /*be able to handle larger numbers. */
parse arg N terms fracs /*obtain optional arguments from the CL*/
if N=='' | N=="," then N= 2 /*Not specified? Then use the default.*/
if terms=='' | terms=="," then terms= 100 /* " " " " " " */
if fracs='' then fracs= '17/91, 78/85, 19/51, 23/38, 29/33, 77/29, 95/23,',
'77/19, 1/17, 11/13, 13/11, 15/14, 15/2, 55/1'
/* [↑] The default for the fractions. */
f= space(fracs, 0) /*remove all blanks from the FRACS list*/
do #=1 while f\==''; parse var f n.# '/' d.# "," f
end /*#*/ /* [↑] parse all the fractions in list*/
#= # - 1 /*the number of fractions just found. */
say # 'fractions:' fracs /*display number and actual fractions. */
say 'N is starting at ' N /*display the starting number N. */
say terms ' terms are being shown:' /*display a kind of header/title. */
do j=1 for terms /*perform the DO loop for each term. */
do k=1 for # /* " " " " " " fraction*/
if N // d.k \== 0 then iterate /*Not an integer? Then ignore it. */
say right('term' j, 35) "──► " N /*display the Nth term with the N. */
N= N % d.k * n.k /*calculate next term (use %≡integer ÷)*/
iterate j /*go start calculating the next term. */
end /*k*/ /* [↑] if an integer, we found a new N*/
end /*j*/ /*stick a fork in it, we're all done. */