MEX and Matlab - Check if an output is skipped/unused, i.e. marked with tilde (~)
2 次查看(过去 30 天)
显示 更早的评论
Hi,
Is there a way in the MEX API to check whether an output was skipped, i.e. marked with a tilde (~)? Specifically, suppose I do:
[~,y]=myfunc(x);
In MEX, nlhs is set to 2. Is there a way to determine that plhs[0] is unwanted?
How about in Matlab .m code? I could then write a wrapper accordingly for the myfunc mex file (not ideal, but would work).
Cheers, Alex.
p.s. I have already seen this (and am aware I could write separate functions, but it would be infinitely better to detect the tilde)
1 个评论
Bernt Nilsson
2018-6-13
I have the same problem, and three years have passed. Is it yet possible to detect the tilde?
回答(1 个)
Jan
2015-2-7
编辑:Jan
2015-2-7
There is no way, as far as I know neither officially nor undocumented.
Instead of coding the unwanted outputs by the tilde, using a clear and clean input argument is better in my opinion. It is much better to see the intention of the programmer eplicitly than a smart and fancy way to hide this inside intelligent parsing.
If you see a foreign code, or a code written by your own some years ago, decide what is nicer:
opt.OutputX_wanted = false;
y = myfunc(x, opt);
or
[~, y] = myfunc(x)
In the first case you can imagine, that myfunc can save some time, in the second this is not expected by experienced Matlab programmers. Although if the 2nd method might save some lines of code or some microseconds of run time, the debug time rules.
2 个评论
Jan
2015-2-8
I agree, that the ~ method is not really usful. Therefore programmers have to use more efficient ways.
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 String Parsing 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!