1. Lucius; median
Lucius,
Very classy apology--exactly the tone I've been hoping for on this list. We
all step over the line sometimes, we show ourselves to be decent, honoable
people by taking ownership of our mistakes and making amends. You have
given us an excellent example.
Thank you also for your excellent info on math. Two added points:
1. As well as the overflow problem you explained
function abs(atom x)
return sqrt(x*x)
end function
will run *significantly* slower than
function abs(atom x)
if x<0 then
return -x
else
return x
end if
end function
2. With regard to medians, your thoughts on sorting are right on the
money.
But the code for accessing the middle element needs adjustment:
function median(seqeunce x)
integer len
len=length(x)
if len=0 then return 0 end if
if len>2 then x=sort(x) end if
if remainder(len,2)=1 then
return x[(len+1)/2]
else
return (x[len/2]+x[len/2+1])/2
end if
end function
For an odd number of elements the statistical median is the middle
element (element 5 of a 9-element sequence), but for an even number the
statistical median is the average (arithmetic mean) of the two middle
elements (elements 5 and 6 of a 10-element sequence.)
-- Mike Nelson
