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2016 Update

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Tina Müller 2016-12-05 22:15:40 +01:00
parent 948b86eafa
commit dcf5d15da3
7965 changed files with 139854 additions and 31002 deletions
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46
Task/Pi/REXX/pi.rexx
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@ -1,23 +1,23 @@
/*REXX program spits out digits of π (pi) (one at a time) until Ctrl-Break.*/
parse arg digs . /*obtain optional argument from the CL.*/
if digs=='' | digs=="," then digs=1e6 /*Not specified? Then use one million.*/
fn = 'PI_DIGITS.OUT' /*fileID used for output: the π digits.*/
numeric digits digs /*with bigger digs, spitting is slower.*/
call time 'Reset' /*reset the wall-clock (elapsed) timer.*/
signal on halt /*───► HALT when Ctrl─Break is pressed.*/
pi=0; s=16; r=4; v=5; vv=v*v; g=239; gg=g*g; spit=0; old=
do n=1 by 2 /*calculate π with increasing accuracy */
pi=pi + s/(n*v) - r/(n*g) /* ··· using John Machin's formula.*/
if pi==old then leave /*have we exceeded the DIGITS accuracy?*/
s=-s; r=-r; v=v*vv; g=g*gg /*compute some variables for shortcuts.*/
do j=spit+1 to compare(pi,old) /*spit out some (new) digits of π (pi)*/
parse var pi =(j) spit +1 /*equivalent to: spit=substr(pi,j,1) */
call charout ,spit /*display one (new) decimal digit of π.*/
call charout fn,spit /*··· and also write π digit to a file.*/
end /*j*/ /* [↑] 0, 1, or 2 decimal dig are spit*/
spit=j-1 /*adjust for DO loop index increment.*/
old=pi /*use "OLD" value for the next COMPARE.*/
end /*n*/
say /*stick a fork in it, we're all done. */
halt: say n%2+1 'iterations took' format(time("Elapsed"),,2) 'seconds.'
/*REXX program spits out decimal digits of pi (one digit at a time) until Ctrl-Break.*/
parse arg digs oFID . /*obtain optional argument from the CL.*/
if digs=='' | digs=="," then digs=1e6 /*Not specified? Then use the default.*/
if oFID=='' | oFID=="," then oFID='PI_SPIT.OUT' /* " " " " " " */
numeric digits digs /*with bigger digs, spitting is slower.*/
call time 'Reset' /*reset the wall─clock (elapsed) timer.*/
signal on halt /*───► HALT when Ctrl─Break is pressed.*/
pi=0; v=5; vv=v*v; g=239; gg=g*g; spit=0 /*assign some values to some variables.*/
s=16 /*calculate π with increasing accuracy */
r=4; do n=1 by 2 until old=pi; old=pi /*just calculate pi with odd integers*/
pi=pi + s/(n*v) - r/(n*g) /* ··· using John Machin's formula.*/
if pi==old then leave /*have we exceeded the DIGITS accuracy?*/
s=-s; r=-r; v=v*vv; g=g*gg /*compute some variables for shortcuts.*/
do j=spit+1 to compare(pi,old) /*spit out some (new) digits of π (pi)*/
parse var pi =(j) spit +1 /*equivalent to: spit=substr(pi,j,1) */
call charout ,spit /*display one (new) decimal digit of π.*/
call charout oFID,spit /*··· and also write π digit to a file.*/
end /*j*/ /* [↑] 0, 1, or 2 decimal dig are spit*/
spit=j-1 /*adjust for DO loop index increment.*/
end /*n*/
say /*stick a fork in it, we're all done. */
exit: say; say n%2+1 'iterations took' format(time("Elapsed"),,2) 'seconds.'; exit
halt: say; say 'PI_SPIT halted via use of Ctrl-Break.'; signal exit /*show iterations.*/