Extract data by skipping few numbers

I tried to read binary data file in 1D and reshape this into 3D array, and it worked.

But since the data is very large, I want to skip few numbers. Full data size is 1024*1024*1024, so if I skip 2, then the array will be 512*512*512.

For now I am doing that by the code below. My question is, is there any way to reduce redundant arrays?

nx = 1024;
iskip = 4;


file1 = fopen(fullfile('E:\AUTOIGNITION\Z1\Velocity1_inertHIT.bin'),'r');
A = fread(file1,nx*nx*nx,'float32');
%A = fread(file1,nx/skip*nx/skip*nx/skip,'float32',skip);

fclose(file1);

U1 = reshape(A,nx,nx,nx);
U = zeros(nx/iskip,nx/iskip,nx/iskip);
for i = 1:nx/iskip
    for j = 1:nx/iskip
        for k = 1:nx/iskip
            U(i,j,k) = U1(1+iskip*(i-1),1+iskip*(j-1),1+iskip*(k-1));
        end
    end
end

Answer 1

[Walter Roberson]

After you do the reshape forming U1, then just do

U = U1(1:iskip:end, 1:iskip:end, 1:iskip:end);