Meissel–Mertens constant: Difference between revisions
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*** last result: cpu time 1min, 18,085 ms, real time 1min, 18,094 ms.
?</pre>
=={{header|Phix}}==
Converges very slowly, I started running out of memory (from generating so many primes) before it showed any signs of getting stuck.
<!--<syntaxhighlight lang="phix">(phixonline)-->
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span> <span style="color: #000080;font-style:italic;">-- (but perhaps a bit too slow)</span>
<span style="color: #008080;">constant</span> <span style="color: #000000;">mmc</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0.2614972128476427837554268386086958590516</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">smmc</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"0.2614972128476427837554268386086958590516"</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">t</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0.57721566490153286</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">dpa</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">p10</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span>
<span style="color: #004080;">integer</span> <span style="color: #000000;">pn</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">adp</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">0</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">st</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"0"</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">fmt</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">"%.0f"</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Primes added M\n"</span><span style="color: #0000FF;">)</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"------------ --------------\n"</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">while</span> <span style="color: #000000;">adp</span><span style="color: #0000FF;"><=</span><span style="color: #000000;">10</span> <span style="color: #008080;">do</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">rp</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">1</span><span style="color: #0000FF;">/</span><span style="color: #7060A8;">get_prime</span><span style="color: #0000FF;">(</span><span style="color: #000000;">pn</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">t</span> <span style="color: #0000FF;">+=</span> <span style="color: #7060A8;">log</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">-</span><span style="color: #000000;">rp</span><span style="color: #0000FF;">)</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">rp</span>
<span style="color: #008080;">if</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">-</span><span style="color: #000000;">mmc</span><span style="color: #0000FF;">)<</span><span style="color: #000000;">dpa</span> <span style="color: #008080;">then</span>
<span style="color: #004080;">string</span> <span style="color: #000000;">ft</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">fmt</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">trunc</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">*</span><span style="color: #000000;">p10</span><span style="color: #0000FF;">)/</span><span style="color: #000000;">p10</span><span style="color: #0000FF;">)</span> <span style="color: #000080;font-style:italic;">-- (as below)</span>
<span style="color: #008080;">if</span> <span style="color: #000000;">ft</span><span style="color: #0000FF;">=</span><span style="color: #000000;">st</span> <span style="color: #008080;">then</span>
<span style="color: #000080;font-style:italic;">--
-- We have to artifically calculate a "truncated t", aka tt,
-- to prevent say 0.2..299[>5..] being automatically rounded
-- by printf() to 0.2..300, otherwise it just "looks wrong".
--</span>
<span style="color: #004080;">atom</span> <span style="color: #000000;">tt</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">trunc</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">*</span><span style="color: #000000;">1e12</span><span style="color: #0000FF;">)/</span><span style="color: #000000;">1e12</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"%,11d %0.12f (accurate to %d d.p.)\n"</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">pn</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">tt</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">adp</span><span style="color: #0000FF;">})</span>
<span style="color: #000000;">adp</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
<span style="color: #000000;">fmt</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"%%.%df"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">adp</span><span style="color: #0000FF;">)</span>
<span style="color: #000000;">st</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">smmc</span><span style="color: #0000FF;">[</span><span style="color: #000000;">1</span><span style="color: #0000FF;">..</span><span style="color: #000000;">2</span><span style="color: #0000FF;">+</span><span style="color: #000000;">adp</span><span style="color: #0000FF;">]</span>
<span style="color: #000000;">dpa</span> <span style="color: #0000FF;">/=</span> <span style="color: #000000;">10</span>
<span style="color: #000000;">p10</span> <span style="color: #0000FF;">*=</span> <span style="color: #000000;">10</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
<span style="color: #000000;">pn</span> <span style="color: #0000FF;">+=</span> <span style="color: #000000;">1</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">while</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"(actual value 0.26149721284764278375542683860869)\n"</span><span style="color: #0000FF;">)</span>
<!--</syntaxhighlight>-->
{{out}}
<small>(Couldn't be bothered with making it an inner loop to upgrade the "accurate to 4dp" to 5dp)</small>
<pre>
Primes added M
------------ --------------
1 0.384068484341 (accurate to 0 d.p.)
3 0.288793158252 (accurate to 1 d.p.)
6 0.269978901636 (accurate to 2 d.p.)
38 0.261990332075 (accurate to 3 d.p.)
1,940 0.261499998883 (accurate to 4 d.p.)
1,941 0.261499997116 (accurate to 5 d.p.)
5,471 0.261497999951 (accurate to 6 d.p.)
34,891 0.261497299999 (accurate to 7 d.p.)
303,447 0.261497219999 (accurate to 8 d.p.)
9,246,426 0.261497212999 (accurate to 9 d.p.)
24,304,615 0.261497212899 (accurate to 10 d.p.)
(actual value 0.26149721284764278375542683860869)
</pre>
=={{header|Wren}}==
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