Replacing NaN with variable data

hi, I have this matrices : u=[0;0;0;0;NaN;NaN;NaN;NaN;NaN;NaN;NaN;NaN] and up=[2;4;5;3;1;7;3;41] I wanna replace nan in "u" matrix with the variants of "up" matrix please answer to my question if you can , I really need the answer immediately, thanks

Answer 1

[Thorsten]

This works is you have at least N values in up, where N is the number of NaNs in u.

 u=[0;0;0;0;NaN;NaN;NaN;NaN;NaN;NaN;NaN;NaN]; 
 up=[2;4;5;3;1;7;3;41]

 ind = isnan(u)
 u(ind) = up(1:nnz(ind))

[keyvan ebrahimpour]

thank you my friend