"any" returns the wrong logical value from a 3D matrix

Hello everyone,

I have a 3D matrix (I called it z_wz_b_m), which has a dimension of 225x1x118.

The first element set of this matrix looks as follow:

val(:,:,1) =

0.7610

4.7390

0.6440

4.7390

4.7390

0.7610

0.7610

0.7610

0.7610

0.7610

0.7610

0.7610

4.7390

0.7610

4.7390

0.7610

4.7390

4.7390

0.8469

0.7610

0.7610

0.7610

0.7610

4.7390

0.7610

4.7390

4.7390

4.7390

0.6482

0.7610

0.7610

0.7610

0.7610

0.7610

0.7610

0.7610

0.7610

4.7390

4.7390

0.7610

4.7390

0.7610

4.7390

4.7390

4.7390

0.7610

0.7610

0.7610

0.7610

0.7610

0.7610

4.7390

0.7610

4.7390

4.7390

4.7390

4.7390

4.7390

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

0.6440

4.7390

4.7390

0.6440

4.7390

4.7390

1.2188

0.7610

4.7390

4.7390

4.7390

0.7610

4.7390

4.7390

0.8067

0.7610

4.7390

4.7390

4.7390

0.8469

0.7610

4.7390

0.7610

4.7390

0.7610

4.7390

4.7390

4.7390

4.7390

0.6482

0.7610

4.7390

0.7610

4.7390

0.7610

4.7390

0.7610

1.3193

4.7390

4.7390

1.1408

0.7610

4.7390

4.7390

4.7390

4.7390

0.7610

0.8724

0.7768

4.7390

0.7768

4.7390

Obviously, it contains values, which are smaller than 0.7. However, when I put

any(z_wz_b_m(:,:,1))<=0.7

it returns 0.

I expect to get 1, since some values are in fact smaller than 0.7.

Could anybody help me to find the error?

[Yazan]

any returns a binary value (0 or 1), why are you comparing this with 0.7??? Does not make sense! You need to compare the values z_wz_b_m(:,:,1) with 0.7, then use any.

any(z_wz_b_m(:,:,1)<=0.7)

[Leonardus Yudha Septian Sutanto]

I see, I got it now! Thanks a lot!

Answer 1

[DGM]

The input to any() is (implicitly) logical. MATLAB considers nonzero numeric values to be logical true.

In this case, you're testing whether any of the values in your numeric array are nonzero (which is true), and then you're comparing the output (scalar logical true) to see if it's less than or equal to 0.7, which is false.

any(z_wz_b_m(:,:,1))<=0.7

Do this instead.

any(z_wz_b_m(:,:,1)<=0.7)