Access value in cell arrays
조회 수: 2 (최근 30일)
이전 댓글 표시
A{1,1}.str = 1;
A{2,1}.str = 2;
... (so on)
A{10,1}.str = 10;
Can I say:
B = A{:,1}.str;
so that:
B=[1 2 3 4 5 6 7 8 9 10];
Thanks very much
댓글 수: 2
per isakson
2013년 6월 29일
Is A supposed to be a cell arrays of structures?
A field named "str" holding a numerical value isn't that confusing?
채택된 답변
per isakson
2013년 6월 29일
편집: per isakson
2013년 6월 29일
What you look for can be achieved with cellfun, see below.
Indexing like C{:}.field is not supported (AFAIK).
The script
S1.field=1;
S2.field=2;
S3.field=3;
C = { S1, S2, S3 };
C{1}.field
C{2}.field
C{3}.field
C{:}.field
returns
ans =
1
ans =
2
ans =
3
Bad cell reference operation.
And
vec = cellfun( @(S) S.field, C, 'uni', true )
returns
ans =
1 2 3
.
EDIT
The single command with cellfun is justified in case the cells of the cell array contain structures with only some fields in common.
Example:
S1.field=1;
S2.field=2;
S3.field=3;
S1.field1=1;
S2.field2=2;
S3.field3=3;
C = { S1, S2, S3 };
vec = cellfun( @(S) S.field, C, 'uni', true )
returns
vec =
1 2 3
댓글 수: 4
Matt J
2013년 6월 29일
You can Accept-click per's Answer, then, since that was what you were looking for.
추가 답변 (2개)
Matt J
2013년 6월 29일
편집: Matt J
2013년 6월 29일
No. You can do this instead
A(1).str = 1;
A(2).str = 2;
...
A(10).str = 10;
B=[A(:).str]
댓글 수: 3
Matt J
2013년 6월 29일
It would not make sense to hold structures having the same fields inside cells. It just makes them harder to get to (as you've discovered).
per isakson
2013년 6월 29일
편집: per isakson
2013년 6월 29일
I agree.
However, for some reason the cell array may contain structures with only some fields in common.
James Tursa
2013년 6월 29일
Another variation:
x = [A{:,1}];
B = [x.str];
댓글 수: 2
Matt J
2013년 6월 30일
TN, if James solution works for you, there is really no reason to be carrying around A. You may as well just use x. As per said, it might make sense if A{i} were structs with different fields, but James' approach will not work if that is the case.
참고 항목
카테고리
Help Center 및 File Exchange에서 Graphics Object Programming에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!