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Revision as of 15:33, 31 December 2021

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→‎{{header|Phix}}: added syntax colouring, marked p2js compatible
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=={{header|Phix}}==
The obvious simple way:
<!--<lang Phix>function median(sequence sphixonline)-->
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
atom res=0
<span style="color: #008080;">function</span> <span style="color: #000000;">median</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">)</span>
integer l = length(s), k = floor((l+1)/2)
<span style="color: #004080;">atom</span> <span style="color: #000000;">res</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span>
if l then
<span style="color: #004080;">integer</span> <span style="color: #000000;">l</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">k</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">((</span><span style="color: #000000;">l</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>
s = sort(s)
<span style="color: #008080;">if</span> <span style="color: #000000;">l</span> <span style="color: #008080;">then</span>
res = s[k]
<span style="color: #000000;">s</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sort</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">)</span>
if remainder(l,2)=0 then
<span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">k</span><span style="color: #0000FF;">]</span>
res = (res+s[k+1])/2
<span style="color: #008080;">if</span> <span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #000000;">l</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
end if
<span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">res</span><span style="color: #0000FF;">+</span><span style="color: #000000;">s</span><span style="color: #0000FF;">[</span><span style="color: #000000;">k</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">])/</span><span style="color: #000000;">2</span>
end if
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
return res
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
end function</lang>
<span style="color: #008080;">return</span> <span style="color: #000000;">res</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<!--</lang>-->
It is also possible to use the [[Quickselect_algorithm#Phix|quick_select]] routine for a small (20%) performance improvement,
which as suggested below may with luck be magnified by retaining any partially sorted results.
<!--<lang Phix>function medianq(sequence sphixonline)-->
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
atom res=0, tmp
<span style="color: #008080;">function</span> <span style="color: #000000;">medianq</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">)</span>
integer l = length(s), k = floor((l+1)/2)
<span style="color: #004080;">atom</span> <span style="color: #000000;">res</span><span style="color: #0000FF;">=</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">tmp</span>
if l then
<span style="color: #004080;">integer</span> <span style="color: #000000;">l</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">),</span> <span style="color: #000000;">k</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">floor</span><span style="color: #0000FF;">((</span><span style="color: #000000;">l</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>
{s,res} = quick_select(s,k)
<span style="color: #008080;">if</span> <span style="color: #000000;">l</span> <span style="color: #008080;">then</span>
if remainder(l,2)=0 then
<span style="color: #0000FF;">{</span><span style="color: #000000;">s</span><span style="color: #0000FF;">,</span><span style="color: #000000;">res</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">quick_select</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">,</span><span style="color: #000000;">k</span><span style="color: #0000FF;">)</span>
{s,tmp} = quick_select(s,k+1)
<span style="color: #008080;">if</span> <span style="color: #7060A8;">remainder</span><span style="color: #0000FF;">(</span><span style="color: #000000;">l</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">)=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
res = (res+tmp)/2
<span style="color: #0000FF;">{</span><span style="color: #000000;">s</span><span style="color: #0000FF;">,</span><span style="color: #000000;">tmp</span><span style="color: #0000FF;">}</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">quick_select</span><span style="color: #0000FF;">(</span><span style="color: #000000;">s</span><span style="color: #0000FF;">,</span><span style="color: #000000;">k</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
end if
<span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">(</span><span style="color: #000000;">res</span><span style="color: #0000FF;">+</span><span style="color: #000000;">tmp</span><span style="color: #0000FF;">)/</span><span style="color: #000000;">2</span>
end if
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
return res -- (or perhaps return {s,res})
<span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
end function</lang>
<span style="color: #008080;">return</span> <span style="color: #000000;">res</span> <span style="color: #000080;font-style:italic;">-- (or perhaps return {s,res})</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
<!--</lang>-->
 
=={{header|Phixmonti}}==
Petelomax
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