how can i split matrix into two part?

i have this matrix

PP =
    11     8     2    10     1     4     6     5     9     7    12     3
     4     3     5     7     6     9    11     1     2     8    12    10
     4    11     9    10    12     2     6     5     8     1     7     3
     3     9     2     7     6     8    11    12     1     4    10     5
     

i want to split this matrix into to part

so code like this

v=2
p1=[PP(1:v,:)];
p2=[PP(PP-v+1:end,:)];

v=2 means that i want to split into two row..

the 1st and 2nd row is in p1, and the 3rd and 4th in p2..

for p1 i got the code correctly however for p2 i didnt get it right

i put v because if the matrix change to 6x6 or 10x10 , i want to change the value of v into what ever i want..

[sharifah shuthairah syed abdullah]

v=2 acually from another part of the coding so i cannot change that part..

[Stephen23]

Note that in MATLAB square brackets are a concatenation operator. In your code the square brackets are totally superfluous, and you should get rid of them.

https://www.mathworks.com/matlabcentral/answers/35676-why-not-use-square-brackets

[sharifah shuthairah syed abdullah]

ooo...thank you..

[ACHAMMA JACOB]

hello sir,

actually i am having a matrix 201x301. I need to spli it into 2 rows and N columns. how is it possible sir?

[Shafiqur Rahman]

simply

pp=(5 row,5 clm)

p1=pp(1:2,:);

p2=pp(3:end,:)

Answer 1

[Stephen23]

p1 = PP(1:v,:);
p2 = PP(v+1:end,:);

Note that I got rid of the superfluous square brackets.

[sharifah shuthairah syed abdullah]

thank you so much.. i have been stuck several week on this part.. thank you so much..

Answer 2

[madhan ravi]

Don’t think of naming variables dynamically ( https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval#answer_274740 )

v=2;
P=reshape(PP,v,size(PP,2),[])

[sharifah shuthairah syed abdullah]

i try using the code u give.. the result show that its change the value inside the matrix..

for example

PP =
    11     5     6     3    10     7     1     2     4     9     8    12
     4    10     1     2     8    12     3     5     6     7    11     9
     6     3     5    10    12     1     2     7     9     4    11     8
    12     1    10     8     2     5     4     6    11     9     7     3    

the result

    P=reshape(PP,v,size(PP,2),[])
P(:,:,1) =
    11     6     5     3     6     5     3    10    10    12     7     1
     4    12    10     1     1    10     2     8     8     2    12     5
P(:,:,2) =
     1     2     2     7     4     9     9     4     8    11    12     8
     3     4     5     6     6    11     7     9    11     7     9     3

Answer 3

[Fahimeh Yeganeh]

I have a matrix as below;

1 0.7494 -32.75 -25.375

2 0.91315 -9.875 -10.75

2 1 -3 -7.375

1 1.8799 -8.875 -5.875

2 2.29885 30.875 40.50

2 2.46570 -2.25 3.875

I would like to split it into 'n' number of matrices based on the variations in the first column. In the above example n=2.

Doese anyone know how I can do it in Matlab?

Thanks

Answer 4

[Fahimeh Yeganeh]

I mean I would like to split it as the following 2 matrices

1 0.7494 -32.75 -25.375

1 1.8799 -8.875 -5.875

and

2 0.91315 -9.875 -10.75

2 1 -3 -7.375

2 2.29885 30.875 40.50

2 2.46570 -2.25 3.875

[Rounak Saha Niloy]

Use unique function to get the index of items from the first column. Now use that index to split your matrix.