A row vector that matches all similar rows in a matrix to group be them in a scatter plot

I have a huge matrix where I want to split them into smaller group based on certain criteria where all the rows are matching. For simplicity I have created the following example to demonstrate what I want to do as below

%The main Matrix
A          = [1 1 1 40 50; 0 0 0 60 40; 2 2 2 20 10; 3 3 3 40 30; 1 1 1 60 70; 0 0 0 20 10];

% find the unique values as below
B          = unique(A(:,1:3),'row');
[Lia,Locb] = ismember(A(:,1:3),B,'row');

% create the New Mat
NewMat     = [A , Locb]; 

NewMat =

1 1 1 40 50 2

0 0 0 60 40 1

2 2 2 20 10 3

3 3 3 40 30 4

1 1 1 60 70 2

0 0 0 20 10 1

I'm looking for a way to split the new matrix (NewMat) into new matrixes based on their Locb values which are located in column 6. To get the following:

NewMat_1 = [     0     0     0    60    40     1;     0     0     0    20    10     1]
NewMat_2 = [     1     1     1    40    50     2;     1     1     1    60    70     2]
NewMat_3 = [     2     2     2    20    10     3 ]
NewMat_4 = [     3     3     3    40    30     4 ]

Then plot them all in one scatter plot with different group color 


scatter(NewMat_1(:,4), NewMat_1(:,4)); hold on  
scatter(NewMat_2(:,4), NewMat_1(:,4)); hold on  
scatter(NewMat_3(:,4), NewMat_1(:,4)); hold on  
scatter(NewMat_4(:,4), NewMat_1(:,4)); hold on  
legend('1','2','3','4')

Anyway to help please.

[Yaser Khojah]

I have created something like this but looking for a better way

A          = [1 1 1 40 50; 0 0 0 60 40; 2 2 2 20 10; 3 3 3 40 30; 1 1 1 60 70; 0 0 0 20 10];
B          = unique(A(:,1:3),'row');
[Lia,Locb] = ismember(A(:,1:3),B,'row');
NewMat     = [A , Locb]; 


Un_Locb = unique(Locb); 

for i = 1:length(Un_Locb)
    
    row = find(NewMat(:,6)==Un_Locb(i)); 
    
    M{i}  = NewMat(row,:); 
    
    
end 

[madhan ravi]

Is M your desired result?

[Yaser Khojah]

Hello Madhan, M can be the result or any other way to get all the rows that in A (:,1:3) share similar values as in B. ismember function shows only one row index and does not show the rest. I want to see all the indexes in an efficient way rather than using find function since I have a huge matrix.

[madhan ravi]

Please explicitly show how your m should look like to get a clear picture of your goal?

Answer 1

[Jan]

A          = [1 1 1 40 50; 0 0 0 60 40; 2 2 2 20 10; 3 3 3 40 30; 1 1 1 60 70; 0 0 0 20 10];
B          = unique(A(:,1:3),'row');
[Lia,Locb] = ismember(A(:,1:3),B,'row');
NewMat     = [A , Locb];

M = splitapply(@(x){x}, NewMat, Locb)

By the way, this can be improved:

    row = find(NewMat(:,6)==Un_Locb(i));
    %     ^^^^  omit this for faster logical indexing
    M{i}  = NewMat(row,:);