Numerical integration: Difference between revisions

Numerical integration (view source)

Revision as of 14:25, 16 May 2020

22 bytes added , 4 years ago

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→‎{{header|REXX}}: changed wording in the REXX section header, optimized one procedure (about 5% faster).

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rosettacode>Gerard Schildberger

Revision as of 13:56, 16 May 2020 (view source) rosettacode>Gerard Schildberger m (used a blank to not split the pseudocode paragraph into two parts.) ← Older edit		Revision as of 14:25, 16 May 2020 (view source) rosettacode>Gerard Schildberger m (→‎{{header\|REXX}}: changed wording in the REXX section header, optimized one procedure (about 5% faster).) Newer edit →
Line 4,285: =={{header\|REXX}}== Note:   there was virtually no difference in accuracy between   '''numeric digits 9'''   (the default)   and   '''numeric digits 20'''. <lang rexx>/REXX pgm performs numerical integration using 5 different algorithms and show results./ numeric digits 20 /use twenty decimal digits precision. / Line 4,308: /──────────────────────────────────────────────────────────────────────────────────────/ left_rect: procedure expose test; parse arg a,b,n; $= 0; h= (b-a)/n do x=a by h for n; $= $ + f(x); end /x/ return $h/1 /──────────────────────────────────────────────────────────────────────────────────────/ midpoint_rect: procedure expose test; parse arg a,b,n; $= 0; h= (b-a)/n do x=a+h/2 by h for n; $= $ + f(x); end /x/ return $h/1 /──────────────────────────────────────────────────────────────────────────────────────/ right_rect: procedure expose test; parse arg a,b,n; $= 0; h= (b-a)/n do x=a+h by h for n; $= $ + f(x); end /x/ return $h/1 /──────────────────────────────────────────────────────────────────────────────────────/ Simpson: procedure expose test; parse arg a,b,n; h= (b-a)/n; hh= h/2 $= f(a + h/2) @= 0; do x=1 for n-1; $hx=hx; $=$+f(a+~~hx~~hx+~~h.5~~hh); @= @+f(a+~~xh~~hx); end /x/ return h (f(a) + f(b) + 4$ + 2@) / 6