MATLAB: How to index a matrix in matlab

arraycell arraysfor loopif statementindexmatrix array

Assume input matrix I as follows:
I = [
100  56  1
100  54  1
100  65  1
101  5  0
101  10  1
101  15  1
101  20  0
101  30  1
101  20  1
101  50  1
198  30  0
198  20  1
203  10  0
203  5  1
203  60  1
203  20  1
203  15  1
44  70  0
44  65  1
44  45  1
44  50  0
44  35  1
44  35  1
44  50  0
44  70  1
44  75  1
44  65  1
];
I want to create 3 matrix based on the I matrix:
Matrix A:
Based on the unique ID in first column of matrix A, I want to generate numbers if ID is same then corresponding cell get same number and if the ID changed, the corresponding ID reset numbers. Also, if in the same ID number, from the third column in matrix I, there was an interrupt with value 0, then number reset and continue (see the figure below).
Matrix B:
Based on the out put of matrix A, I want to count how many number generated for every ID (and if there was an interrupt with 0). See the figure below.
Matrix C:
Based on the out put of matrix A, I want to sum up the corresponding cells from second column in matrix I. See the figure below.
A = [
100  1
100  1
100  1
101  1
101  1
101  1
101  2
101  2
101  2
101  2
198  1
198  1
203  1
203  1
203  1
203  1
203  1
44  1
44  1
44  1
44  2
44  2
44  2
44  3
44  3
44  3
44  3
];
B = [
100  3
101  3
101  4
198  2
203  5
44  3
44  3
44  4
];
C = [
100  175
101  30
101  120
198  50
203  110
44  180
44  120
44  260
];

Best Answer

Array A
>> [U,X,Y] = unique(I(:,1));
>> [~,X] = sort(X);
>> [~,X] = sort(X);
>> fun = @(v){cumsum(v==0)+(v(1)==1)};
>> Z = accumarray(X(Y),I(:,3),[],fun);
>> A = [I(:,1),cell2mat(Z)]
A =
 100     1
 100     1
 100     1
 101     1
 101     1
 101     1
 101     2
 101     2
 101     2
 101     2
 198     1
 198     1
 203     1
 203     1
 203     1
 203     1
 203     1
  44     1
  44     1
  44     1
  44     2
  44     2
  44     2
  44     3
  44     3
  44     3
  44     3
Array B
>> V = [true;any(diff(A,1,1),2)]
>> W = accumarray(cumsum(V),ones(size(V)));
>> B = [I(V,1),W]
B =
 100     3
 101     3
 101     4
 198     2
 203     5
  44     3
  44     3
  44     4
Array C
>> T = accumarray(cumsum(V),I(:,2));
>> C = [I(V,1),T]
C =
 100   175
 101    30
 101   120
 198    50
 203   110
  44   180
  44   120
  44   260
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