How to assign values to vector using linear indexing in matlab?

Question

I have a vector with NaNs:

v1 = [NaN NaN NaN NaN NaN];

another vector with different values:

v2 = [1 4 6 8 9];

and linear index:

idx = [1 0 4 0 3];

I would like to assign values in v2 to v1 according to linear index so the result would be:

v1 = [1 NaN 8 NaN 6];

Answer 1

v1(idx ~= 0) = v2(idx(idx ~= 0))

This takes

"The values in v1 where idx is not equal to zero"

and assigns them the values in

" v2 , at indexes idx , where idx is also not equal to zero"