Meissel–Mertens constant: Difference between revisions
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(→{{header|Wren}}: Added Analytic method.) |
(Meissel–Mertens constant in various BASIC dialents (BASIC256, Run BASIC and Yabasic)) |
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after 1270607 primes, the approximation is: 0.261497214255, last prime considered: 19999999 |
after 1270607 primes, the approximation is: 0.261497214255, last prime considered: 19999999 |
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</pre> |
</pre> |
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=={{header|BASIC}}== |
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==={{header|BASIC256}}=== |
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{{trans|FreeBASIC}} |
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<syntaxhighlight lang="freebasic">Euler = 0.5772156649 |
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m = 0 |
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for x = 2 to 1e6 # more prime numbers do not add more precision |
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if isPrime(x) then m += log(1-(1/x)) + (1/x) |
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next x |
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print "MM = "; Euler + m |
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print Euler |
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end |
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function isPrime(v) |
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if v < 2 then return False |
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if v mod 2 = 0 then return v = 2 |
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if v mod 3 = 0 then return v = 3 |
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d = 5 |
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while d * d <= v |
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if v mod d = 0 then return False else d += 2 |
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end while |
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return True |
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end function</syntaxhighlight> |
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{{out}} |
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<pre>MM = 0.26149724673</pre> |
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==={{header|Run BASIC}}=== |
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{{trans|FreeBASIC}} |
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<syntaxhighlight lang="lb">function isPrime(n) |
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if n < 2 then isPrime = 0 : goto [exit] |
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if n = 2 then isPrime = 1 : goto [exit] |
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if n mod 2 = 0 then isPrime = 0 : goto [exit] |
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isPrime = 1 |
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for i = 3 to int(n^.5) step 2 |
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if n mod i = 0 then isPrime = 0 : goto [exit] |
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next i |
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[exit] |
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end function |
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e = 0.5772156 |
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for x = 2 to 100000 ' more prime numbers do not add more precision |
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if isPrime(x) then m = m + log(1-(1/x)) + (1/x) |
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next x |
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print "MM = "; e + m</syntaxhighlight> |
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{{out}} |
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<pre>MM = 0.261274</pre> |
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==={{header|Yabasic}}=== |
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{{trans|FreeBASIC}} |
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<syntaxhighlight lang="freebasic">e = 0.5772156 |
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for x = 2 to 1e6 // more prime numbers do not add more precision |
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if isPrime(x) m = m + log(1-(1/x)) + (1/x) |
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next x |
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print "MM = ", e + m |
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end |
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sub isPrime(v) |
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if v < 2 return False |
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if mod(v, 2) = 0 return v = 2 |
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if mod(v, 3) = 0 return v = 3 |
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d = 5 |
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while d * d <= v |
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if mod(v, d) = 0 then return False else d = d + 2 : fi |
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wend |
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return True |
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end sub</syntaxhighlight> |
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{{out}} |
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<pre>MM = 0.261497</pre> |
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=={{header|FreeBASIC}}== |
=={{header|FreeBASIC}}== |
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