Split vector A into smaller vectors based on vector B

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I have two vectors of same lenght. Vector A contains angle data, and vector B contains gait phase (0=other;1=stand; 2=swing).
I want to split vector A into smallers vector for each individual gait phase cointaining only data during the stance and swing.
My data is as follows:
Vector A Vector B
1.2 1
1.3 1
1.4 1
1.5 2
1.6 2
1.7 0
1.8 0
1.9 2
1.10 2
1.11 1
1.12 1
1.13 0
1.14 1
1.15 1
Then I want to split A into...
Vector C Vector D Vector E Vector F Vector G
1.2 1.5 1.9 1.11 1.14
1.3 1.6 1.10 1.12 1.15
1.4
Thus splitting the data into small vector everytime Vector B changes but ignoring the values of A when Vector B is zero...
Thank you!
  1 Comment
Francisco Anaya
Francisco Anaya on 26 Mar 2019
Before I was using the following, but I didnt have the third condition in B when b is equal to zero...
A = [1.2;1.3;1.4;1.5;1.6;1.7;1.8;1.9;1.1;1.11;1.12;1.13;1.14];
B = [1;1;1;2;2;2;2;2;2;1;1;1;1];
X = cumsum([true;0~=diff(B)])
C = accumarray(X,A,[],@(v){v});
C{:}
ans =
1.2000
1.3000
1.4000
ans =
1.5000
1.6000
1.7000
1.8000
1.9000
1.1000
ans =
1.1100
1.1200
1.1300
1.1400

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Answers (1)

KSSV
KSSV on 26 Mar 2019
data = [1.2 1
1.3 1
1.4 1
1.5 2
1.6 2
1.7 0
1.8 0
1.9 2
1.10 2
1.11 1
1.12 1
1.13 0
1.14 1
1.15 1] ;
vecA = data(:,1) ;
vecB = data(:,2) ;
[C,ia,ib] = unique(vecB) ; % groups
G = length(C) ;
iwant = cell(G,1) ;
for i = 1:G
A = (vecB==C(i))' ;
ii = zeros(size(A));
jj = A > 0;
ii(strfind([0,jj(:)'],[0 1])) = 1;
idx = cumsum(ii).*jj;
iwant{i} = accumarray( idx(jj)',vecA(jj)',[],@(x){x'});
end
  1 Comment
Francisco Anaya
Francisco Anaya on 27 Mar 2019
Edited: Francisco Anaya on 27 Mar 2019
Dear KSSV thank you for your answer. But I have one problem. I have implemented your code as follows:
[C,ia,ib]=unique(r_gait_phase_new); %groups
G=length(C);
iwant=cell(G,1);
for i=1:G
A=(r_gait_phase_new==C(i))';
ii=zeros(size(A));
jj=A>0;
ii(strfind([0,jj(:)'],[0 1]))=1;
idx=cumsum(ii).*jj;
iwant{i}=accumarray(idx(jj)',angle_data_new(jj)',[],@(x){x'});
end
The code works well. However, angle_data_new contains 6 vector data (for 6 different angles, foot, knee and hip). The code you shared only split the data of the first column. How can I obtain the splitted vectors for all 6 vectors contained in angle_data_new??
Thank you so much! You are a lifesaver!

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