How to extract and store parts of a matrix to new matrices

I have read the FAQ to extract parts of an existing matrix

to new matrices only by selection of rows but had no success.

I wish to do the following:

Let M=

1 1

2 2

3 3

4 4

5 5

6 6

7 7

8 8

9 9

10 10

and the following parameters to create a loop:

for k=1:3;

l=(k+1);

m=(2*k)+3;

mk=M(l:m,1:end);

end;

I wished by doing that above to get the following results

for k=1

m1=

2 2

3 3

4 4

5 5

for k=2

m2=

3 3

4 4

5 5

6 6

7 7

for k=3

m3=

4 4

5 5

6 6

7 7

8 8

9 9

and so on. Instead, as result I obtained only:

mk=

4 4

5 5

6 6

7 7

8 8

9 9

It is only the matrix for the last value of k and the index 3 is not

appearing instead of k for mk.

Hopefully someone knows how to fix this problem

Thank you

Emerson

Answer 1

[the cyclist]

In your loop, you are writing to the single variable "mk" over and over again, overwriting the value from the previous loop. Probably the best way to do this is with a "cell array". Each element of the cell array can itself be an array, which is what you want.

Use

 mk{k}=M(l:m,1:end);

inside the loop, where the "k" inside the curly brackets indexes into the cell array. When you are done, your mk variable will have three elements; each will be an array.

(I did not check the rest of your code to see if it is doing what you want.)

[Emerson De Souza]

Hi

thank you a lot for your help.

I wrote as you suggested and obtained what I wanted.

By double clicking on mk in the workspace I observed

in the first row of the variable editor that each cell

is storing one matrix.

I wish you a nice weekend

Emerson