I am using `hist` to compute the number of occurrences of values in a matrix in Matlab. 

I think I am using it wrong because it gives me completely weird results. Could you help me to understand what is going on?

When I run this piece of code I get `countsB` as desired

```
rng default; 
B=randi([0,3],10,1);
idxB=unique(B);
countsB=(hist(B,idxB))';

```

i.e. 

```
B=[3;3;0;3;2;0;1;2;3;3];
idxB=[0;1;2;3];
countsB=[2;1;2;5];

```

When I run this other piece of code I get wrong results for `countsA`

```
A=ones(524288,1)*3418;
idxA=unique(A);
countsA=(hist(A,idxA))';

```

i.e.

```
idxA=3148;
countsA=[zeros(1709,1); 524288; zeros(1708,1)];

```

What am I doing wrong?