Floating point arithmetic. To check for equality (==) always gives problems.
Take a look at
clear all;clc;
n=5;
for i= 1:n
c(:,:,i)=randi([0 3], 2, 2);
end
for i= 1:n
cdct(:,:,i) = dct2(c(:,:,i));
end
cd1_1 = cdct(1,1,:);
lcd1_1 = cd1_1(:);
for j = 1:5
v(j) = lcd1_1(j)==0|lcd1_1(j)==0.5|lcd1_1(j)==1|lcd1_1(j)==1.5|lcd1_1(j)==2|lcd1_1(j)==2.5|lcd1_1(j)==3|lcd1_1(j)==3.5|lcd1_1(j)==4;
end
v
for j=1:5
if lcd1_1(j) == 0
lcd1_1(j) = 10;
elseif lcd1_1(j) == 0.5
lcd1_1(j) = 20;
elseif lcd1_1(j) == 1
lcd1_1(j) = 30;
elseif lcd1_1(j) == 1.5
lcd1_1(j) = 40;
elseif lcd1_1(j) == 2
lcd1_1(j) = 50;
elseif lcd1_1(j) == 2.5
lcd1_1(j) = 60;
elseif lcd1_1(j) == 3
lcd1_1(j) = 70;
elseif lcd1_1(j) == 3.5
lcd1_1(j) = 80;
elseif lcd1_1(j) == 4
lcd1_1(j) = 90;
end
end
lcd1_1