save data all of in loop

I have problem with saving data in loop

I'd like to seperate lon and lat which are saved in num

lon is saved num(1), num(3),num(5)......, and lat is num(2),num(4),num(6)......

That is my code and num

num=xlsread('ENVISAT.ex.xlsx');
num=num(~isnan(num));
num=nonzeros(num)
i=0
lon=[];
lat=[];
for i=1:30
    i=i+um
    lon=num(i+1)
    lat=num(2*i+1)
end 

Answer 1

[Rik]

No loop required:

num=xlsread('ENVISAT.ex.xlsx');
num=num(~isnan(num));
num=nonzeros(num);
lon=num(1:2:end);
lat=num(2:2:end);

In your code it was overwriting the variable every iteration, instead of indexing.

[il147]

It works!!!!!!!!

You are the best :) Thanks!