Comparing arrays and getting the index of extra rows

There are two arrays: A with 8916x3 and B with 6571x3. Each 1x3 set represents xyz coordinates. Array A has some extra coordinates/rows.

I want to compare xyz row by row, and return the index of rows in A that do not exist in B. Then use this index to remove the corresponding extra data from array C (basically C is 8916x3 and it has to be 6571x3 same as B, while keeping the order of rows).

Here's my code but I ge this error: "too many outputs"

[logic,index] =not(ismember(A,B,'rows'))
C(index,:) = [];

Answer 1

[DGM]

Consider:

% example arrays
B = randi(99,5,3)

B = 5×3

78 21 35 61 79 55 47 76 4 33 86 80 72 26 38

A = [B; randi(99,3,3)];
A = A(randperm(size(A,1)),:)

A = 8×3

78 21 35 61 79 55 10 40 11 55 76 42 50 65 26 72 26 38 47 76 4 33 86 80

% i'm assuming C is some separate array?
C = rand(size(A))

C = 8×3

0.5299 0.1604 0.0717 0.6433 0.3189 0.3384 0.6323 0.7470 0.2365 0.1172 0.1725 0.8113 0.3856 0.8772 0.6111 0.0621 0.1053 0.8808 0.9019 0.1290 0.7942 0.0757 0.7127 0.5547

% extract rows from C where A is a member of B, preserving order
C = C(ismember(A,B,'rows'),:)

C = 5×3

0.5299 0.1604 0.0717 0.6433 0.3189 0.3384 0.0621 0.1053 0.8808 0.9019 0.1290 0.7942 0.0757 0.7127 0.5547

[Pelajar UM]

Perfect! Thank you.