Inserting NaN in particular spots of my matrix, all while "preserving" or shifting all other numbers

I want to insert NaN in particular spots of two different sized matrices, with the number I'm "replacing" being shifted "down". For example:

    a = [1 5 NaN 4 NaN 10 3]
    b = [6 1 0 3 5]

I want b to look like:

    b = [6 1 NaN 0 NaN 3 5]

So essentially my NaNs are located in the same index as matrix 1, however, I want to preserve the numbers in b, by moving them down by one index in my new matrix.

Any tips?

Answer 1

[Alfonso Nieto-Castanon]

If I am interpreting correctly (not really sure if this is what you mean by "shifted down") this should do:

 c = nan(size(a));
 c(~isnan(a)) = b;

[alex]

Yup that is what I was looking for. Thanks!