How to reorganize an array given an index

So I have a 65x1 array in which the first 42 elements are numbers and the last 23 elements are NaN. I would like to reorganize the array by putting the NaNs at the end into certain indicies within the array that I have flagged.

More simplistically I want something like this:

array = [1,2,3,4,5,NaN,NaN,NaN];
idx_flag = [1,4,8];

%i want
new_array = [NaN,1,2,NaN,3,4,5,NaN];

Thanks!

Answer 1

[the cyclist]

Here is one way:

% Inputs
array = [1,2,3,4,5,NaN,NaN,NaN];
idx_flag = [1,4,8];

% Get length of array for convenience
L = numel(array);

% Find where the non-NaNs will go
not_idx_flag = setxor(1:L,idx_flag);

% Allocate a new array with all NaNs
new_array = nan(1,L);

% Place the non-NaNs
new_array(not_idx_flag) = array(~isnan(array));

[Scarlet Passer]

Thanks so much it worked great!