Strange behaviour appears like Matlab bug
2 次查看(过去 30 天)
显示 更早的评论
The problem: in each iteration of the loop, a string is created and the converted to the function str2func, e.g. myfunc=str2func(string1); However, after several thousand iterations (not at particular, but seems like random event) myfunc result is the function used some iterations ago, while str2func(string1) as executed directly in matlab command window, returns the function correctly. But if I execute the line myfunc=str2func(string1), myfunc is not the same as str2func(string1) would produce. I am really baffled, seems like out of nowhere - it's like the line "f=1" would return 3 and not 1. Is it a memory thing or what? I have no idea on this.
3 个评论
Cedric
2013-4-8
编辑:Cedric
2013-4-8
Does the pool of these function names contain only your own functions, or does it contain built-ins? If there are built-ins, which ones?
If you had for example an array named funcIds and one of the function names would be funcIds as well, you would use the array by evaluating funcIds(k) until the call to str2func('funcIds'), and the next evaluation of funcIds(k) would be a function call.
Jan's comment/answer is certainly motivated by the fact that we almost never see cases that justify your approach; if you are sure that it is the only possible one, fine, but if you have a doubt we could also discuss the approach.
回答(1 个)
Jan
2013-4-8
编辑:Jan
2013-4-8
if I execute the line myfunc=str2func(string1), myfunc is not the same as str2func(string1) ...
This happens, when there are two functions with the name "string1" in different folders and during the execution the current folder changes. Then you can get two different replies, and both are true.
A similar effect can appear, when a function is read and modified afterwards. Then the function is only reloaded after a clear(string1) or clear('all').
Obviously creating a large number of function handles and perhaps creating M-files dynamically (?) is prone to errors and therefore a bad programming practize.
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息
产品
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!