필터 지우기
필터 지우기

A very odd loop behavior

조회 수: 1 (최근 30일)
Tomas Iesmantas
Tomas Iesmantas 2013년 3월 14일
I encountered a quite odd and unseen behavior in "for" loops. Consider this simple loop:
for i=1:5
Function(rand(1,1))
end
The loop gives the same results, while repeated lines as this:
Function(rand(1,1))
Function(rand(1,1))
Function(rand(1,1))
Function(rand(1,1))
Function(rand(1,1))
Gives 5 different results. What might be the problem? It seems that the "for" loop evaluates the function 5 times with the same argument. This effect is in Wondows, while in Mac system everything goes smoothly and produces different results.
Any advice would be of great value.

채택된 답변

Tomas Iesmantas
Tomas Iesmantas 2013년 3월 14일
What I have already figured out, is that since at every step in the "for" loop I create a new .m file and delete previous file, matlab still have a copy of the old file and executes that old .m instead of newly created. To overcome this I wrote a line to clear old .m file from a memory and everything seems to work properly.
  댓글 수: 2
Jan
Jan 2013년 3월 14일
Creating M-file dynamically is a bad programming practize. It is much more efficient and less prone to errors to call a static function with changing parameters. Any kind of meta-programming increases the effort for debugging substantially, and in all cases I've seen already, the parameterized functions have been more direct and clear.
Tomas Iesmantas
Tomas Iesmantas 2013년 3월 20일
In my case the content of the function varies:number of equations, complexity of equation, parameters of that equation. So it is not possible to creat one function and just feed the parameters. However, I found way better solution - creating the function as a string and not printing it to some m file, but converting it to function with matlab function "str2func".

댓글을 달려면 로그인하십시오.

추가 답변 (1개)

Wayne King
Wayne King 2013년 3월 14일
We don't know anything about Function(), but that is certainly not the case in Windows in general
for ii = 1:5
sum([rand(1,1) 0])
end
  댓글 수: 4
Tomas Iesmantas
Tomas Iesmantas 2013년 3월 14일
Unfortunately the function is very complex and uses another subfunctions as well as construction of txt files, so it would not be of any use to post it here.
Wayne King
Wayne King 2013년 3월 14일
Understood

댓글을 달려면 로그인하십시오.

카테고리

Help CenterFile Exchange에서 Loops and Conditional Statements에 대해 자세히 알아보기

태그

제품

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by