OpenEuphoria

RE: Speed of global function

• Posted by jxliv7 at hotmail.com Aug 16, 2003
• 428 views

Rob, this doesn't make sense.

execution time range in seconds with various iterations and elements
t =  3.02	   30.65      17.03	copy of RDS code
s =  3.96	   39.44      22.3      Ricardo's code
r =  2.3	   22.9       12.65 	RDS code
							
Ricardo, the guy who wrote the original Test2 claimed that it
was sometimes faster than your global routine.

i am thoroughly confused. can you help me see what's going on...?


--Test002.ex-----------  
include misc.e					--for global reverse

--integer a, b, c, d
sequence a, b
atom t, s, r

--global function reverse(sequence s)
---- reverse the top-level elements of a sequence.
---- Thanks to Hawke' for helping to make this run faster.
--	integer lower, n, n2
--	sequence t
--	n = length(s)
--	n2 = floor(n/2)+1
--	t = repeat(0, n)
--	lower = 1
--	for upper = n to n2 by -1 do
--	t[upper] = s[lower]
--	t[lower] = s[upper]
--	lower += 1
--	end for
--	return t
--end function

function test1(sequence in)		--my "copy" of global reverse above
sequence out					
integer stop, start, mid
	stop = length(in)
	out = repeat(0, stop)
	mid = floor(stop/2)+1
	start = 1
	for i = stop to mid by -1 do
		out[start] = in[i]
		out[i] = in[start]
		start += 1
	end for
return out
end function

				--from genfunc.e, a set of general usage routines.
				--Version 1.9 - 2003/06/27
				--Author: Ricardo M. Forno				
function Test2(sequence a)	--a different reverse	
sequence b			--that i would think would be FASTER
integer c				
	c = length(a)
	b = repeat(0, c)
	for i = 1 to c do
	b[c] = a[i]
	c -= 1
	end for
	return b
end function

t = time()				--my duplicate of global reverse
for ii = 1 to 5 do 			--adjust iterations
a = repeat(9, 9999999)		--make file to be reversed
b = test1(a)
end for
t = time() - t

s = time()				--Test2
for ii = 1 to 5 do 			--adjust as above
a = repeat(9, 9999999)		--adjust same as file above
b = Test2(a)
end for
s = time() - s

r = time()				--the global reverse routine
for ii = 1 to 5 do 			--adjust as above
a = repeat(9, 9999999)		--adjust same as file above
b = reverse(a)
end for
r = time() - r


--
jon

jxliv7 at hotmail.com