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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).

madhan ravi
on 23 May 2019

Edited: madhan ravi
on 23 May 2019

Assuming you want to index of the last match in the matrix:

Index=find(a==3,1,'last')

madhan ravi
on 23 May 2019

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().

KALYAN ACHARJYA
on 23 May 2019

Edited: KALYAN ACHARJYA
on 23 May 2019

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

KALYAN ACHARJYA
on 23 May 2019

Yes, we can acess the particular element with 'first' or 'last' as you mentioned below

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