Finding the index of spesific element in a matrix?

693 次查看（过去 30 天）
IBM watson
IBM watson 2019-5-23
评论： Ulika Naidoo 2021-1-22
Lets say we have matrix:
a=[ 2, 3, 5
3, 4, 7
4, 4, 4] ;
I want to know index of a(4) which is the bold 3. This is just an example. I want to learn how to find index of a(n).

请先登录，再回答此问题。

采纳的回答

madhan ravi
madhan ravi 2019-5-23
编辑：madhan ravi 2019-5-23
Assuming you want to index of the last match in the matrix:
Index=find(a==3,1,'last')
https://in.mathworks.com/company/newsletters/articles/matrix-indexing-in-matlab.html - to know more
  13 个评论
显示 11更早的评论
madhan ravi
madhan ravi 2019-5-23
编辑：madhan ravi 2019-5-23
No problem, by the way the original question you asked is totally irrelevant to your latter comment. Please don’t do this in the future riddling the answers.
Look into ind2sub() function to convert the linear indices. To understand what this statement means , you need to read the link which I shared thoroughly and practice. And finally have a look at ind2sub().
IBM watson
IBM watson 2019-5-23
Sure, I didn't do it on purpose. Just could't explain clearly what I want. Thanks again.

请先登录，再进行评论。

更多回答（1 个）

KALYAN ACHARJYA
KALYAN ACHARJYA 2019-5-23
编辑：KALYAN ACHARJYA 2019-5-23
I want to know index of a(4) which is the bold 3
here ......................... this 4^ represent the index, I guessing you are looking for following one.
idx=find(a==3);
One dimentional case array case
>> a=[2,3,5,3,4,7,4,4,4];
>> idx=find(a==7)
idx =
6
>> idx=find(a==3)
idx =
2 4
But Matrices have 2 dimention so indices represents (x,y), where answer will be little different
>> a=magic(3)
a =
8 1 6
3 5 7
4 9 2
>> [r c]=find(a==3)
r =
2
c =
1
  5 个评论
显示 3更早的评论
Stephen23
Stephen23 2020-3-5
"why c =1 ? "
Because the value 3 is in the 1st column.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Matrices and Arrays 的更多信息

标签

Community Treasure Hunt

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

Start Hunting!

Translated by