Is it possible to do multi index command in one line?

조회 수: 7 (최근 30일)
yoohooo's
yoohooo's 2021년 4월 28일
댓글: Steven Lord 2021년 4월 28일
For example, if I want to get number of columns in an array I would have to do the following:
A = [1 2; 3 4];
mySize = size(A);
myCol = mySize(2);
It adds 2 lines and an extra variable in my code. Is it possible to put them in one line like:
myCol = size(A)(2);
Somthing similar to this because this is not the correct syntax.
Thank you very much!

채택된 답변

Matt J
Matt J 2021년 4월 28일
편집: Matt J 2021년 4월 28일
Not in general, but in the case of your example there is a shorter syntax,
myCol=size(A,2)
  댓글 수: 2
yoohooo's
yoohooo's 2021년 4월 28일
Thank you very much. Ah, I forgot we can also do it this way. This is not a good example, then. But yea, so it's not possible.
Steven Lord
Steven Lord 2021년 4월 28일
For some definition of "one line" it is. Write a function:
A = [1 2 3; 4 5 6];
sz = size(A) % for checking
sz = 1×2
2 3
y = getElement(size(A), 2) % The one line
y = 3
But this has a drawback that the shorter syntax doesn't.
size(A, 3) % A has trailing singleton dimensions
ans = 1
y2 = getElement(size(A), 3)
Index exceeds the number of array elements (2).

Error in solution>getElement (line 7)
y = x(whichone);
function y = getElement(x, whichone)
y = x(whichone);
end

댓글을 달려면 로그인하십시오.

추가 답변 (2개)

Matt J
Matt J 2021년 4월 28일
An approximation of this can be enabled through some incredibly convoluted OOP methods
It's not worth it...

Matt J
Matt J 2021년 4월 28일
편집: Matt J 2021년 4월 28일
This is a generally applicable one line implementation, but probably not what you'd hoped for.
A = [1 2; 3 4];
myCol = subsref( size(A), struct('type','()','subs',{{2}}))
myCol = 2

카테고리

Help CenterFile Exchange에서 Creating and Concatenating Matrices에 대해 자세히 알아보기

Community Treasure Hunt

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

Start Hunting!

Translated by