# Re: Is this code computationally economical?

qquito wrote:
Hello, All:

I am using Fortran 90 and have an array, a(1:N), whose some elements
are larger than 0, and others less than or equal to 0.

My task is to find the average of those elements that are larger than
0.

I am thinking to use the code

But since I have to do it with enormous data and many similar
operations, I am wondering if it is as computationally economic as the
following do-loop with an imbedded if-loop:

s=0.0
n=0
do i=1, N

This really isn't the heart of the problem, but by setting
n to 0 before the loop, you've guaranteed that the loop
body will never be executed. Remember that Fortran is
not case sensitive.

Dick Hendrickson
if(a(i)>0.0) then
s=s+a(i)
n=n+1
endif
enddo
average=s/n

I figure that the one-line code given above will have to go through all
the elements twice, and so it is not as computationally economical as
the loop. Is this correct?

--Roland

.

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