how to separate a matrix into 2 vectors

6 visualizzazioni (ultimi 30 giorni)
hello guys, I have a problem with separating a matrix into two vectors, if the last column is 0 or 1.
I explain myself better, I have this matrix but as we can see in the last column I have 1 or 0 right? what I want to do is separate it into two groups for example.
matrix file attached.
matrix
60 13.9713945172825 20 1
59 14.3718712753277 43 1
52 21.1752085816448 20 1
48 12.7771156138259 35 0
48 20.7771156138259 35 0
47 15.1775923718712 28 1
44 18.3790226460073 57 1
41 21.5804529201432 8 1
15 21.9928486293206 29 1
12 21.1942789034565 31 1
Result
vectorof1= [60 13.9713945172825 20 1
59 14.3718712753277 43 1
52 21.1752085816448 20 1
47 15.1775923718712 28 1
44 18.3790226460073 57 1
41 21.5804529201432 8 1
15 21.9928486293206 29 1
12 21.1942789034565 31 1];
vectorof0 = [48 12.7771156138259 35 0
48 20.7771156138259 35 0];
thank you very much in advance.

Risposta accettata

Dave B
Dave B il 17 Mar 2022
Modificato: Dave B il 17 Mar 2022
You can do this pretty easily with some indexing. Here's an example with some random data:
m = [rand(10,2) randi(2,10,1)-1]
m = 10×3
0.6389 0.4429 1.0000 0.0720 0.4878 0 0.8781 0.6126 0 0.8703 0.5697 0 0.4551 0.6683 1.0000 0.8022 0.4067 0 0.2758 0.1283 0 0.5673 0.0117 1.0000 0.1495 0.2832 0 0.0861 0.4779 0
m0 = m(m(:,3)==0,:) % read the right hand side as: from m, take the rows where the third column of m is 0, take all columns
m0 = 7×3
0.0720 0.4878 0 0.8781 0.6126 0 0.8703 0.5697 0 0.8022 0.4067 0 0.2758 0.1283 0 0.1495 0.2832 0 0.0861 0.4779 0
m1 = m(m(:,3)==1,:) % read the right hand side as: from m, take the rows where the third column of m is 1, take all columns
m1 = 3×3
0.6389 0.4429 1.0000 0.4551 0.6683 1.0000 0.5673 0.0117 1.0000
To understand how this works, you can look at what you're feeding in:
ind = m(:,3)==1
ind = 10×1 logical array
1 0 0 0 1 0 0 1 0 0
(importantly it's displayed as 1 and 0, but note it's a "logical array" it's really true, false, false, false, true, ...)

Più risposte (0)

Prodotti


Release

R2020a

Community Treasure Hunt

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

Start Hunting!

Translated by