How do I get index matrix for matrix of values?

hi, can anyone one help me

if i have matrix A i want get index matrix for matrix A

A=[9 5 1

6 5 7

8 4 11]

for exmple The result

A_index =11 12 13

21 22 23

31 32 33

[Cris LaPierre]

It took me a second to figure out how you got your index, only to come back and see that you have removed that from you question.

It might be easier to help if you can share what you have already tried.

[sarah]

i edit qustion and add eample

[Cris LaPierre]

Please share your code, too.

[Fangjun Jiang]

It looks like

Row 1 Column 1, Row 1 Column 2, Row 1 Column 3

Row 2 Column 1, Row 2 Column 2, Row 2 Column 3

I don't know what is the meaning, purpose or usefulnesss for this

Answer 1

[Cris LaPierre]

Now I'm confused, too. You've now posted two completely different types of index matrices. Perhaps instead, could you explain how A maps to A_index?

A_index =11 12 13

21 22 23

31 32 33

As for the current A_index, you can take advantage of implicit expansion to create it.

A_index = (10:10:30)' + (1:3)

A_index = 3×3

11 12 13 21 22 23 31 32 33

[sarah]

think you so much

if i have matrix 16*16 what i do???

[Steven Lord]

Note that elements (1, 11) and (11, 1) will have the same index value (111) with this approach.

[sarah]

I'm trying to build inverse matrix 16 * 16 for s_box matrix

[Cris LaPierre]

I trust you can figure out how to modify the code I shared for 3x3 to create the same pattern for 16x16.

[Cris LaPierre]

I'm trying to build inverse matrix

Have you tried the inv function?

Y = inv(X)

[sarah]

A_index = (10:10:160)' + (1:16)

i think it is better to convert the values to hexadecimal so that there is no duplication

Answer 2

[Fangjun Jiang]

>> [Row,Column]=ind2sub([3,3],1:9)
Row =
     1     2     3     1     2     3     1     2     3
Column =
     1     1     1     2     2     2     3     3     3
     
     
>> [Row,Column]=ind2sub([11,11],[10,11,12, 109,110,111])
Row =
    10    11     1    10    11     1
Column =
     1     1     2    10    10    11