How to save a value from an array if a condition is true

I have two cell arrays "X" and "Y". I need to check if a value in X==1, then save the corresponding Y value. How to do that in a for loop (I have many runs of X and Y)

Answer 1

[Geoff Hayes]

@Tejashree Pawar - do you need to use a loop? For example, if your X and Y arrays are the same dimensions, then (for example) if

X = [1 2 3 1 4 5 1 6 7];
Y = [7 2 2 8 2 2 9 2 2];
Z  = Y(X==1)

then Z is

Z =
     7     8     9

since X==1 returns a logical array of ones and zeros where a one corresponds to the match (to 1) in X. We can then use this logical array to extract those values from Y which match the logical 1.

[Tejashree Pawar]

Hi @Geoff Hayes thanks for the answer! Yes, i need to use it in a for loop because i have multiple X and Y files (CANape test data). X&Y are of same dimension for a given run.

How would i make it work if X and Y were cell arrays?

[Geoff Hayes]

@Tejashree Pawar - couldn't you just use a single for loop to iterate over each element of X and then compare to 1? If true, then extract the equivalent element from Y and insert into an array. Is the problem keeping track of the data from each run?