How do I change the increment in an if statement inside a loop

Hi, I tried googling the previous questions but didn't find a similiar situation.

I've got an if statement inside a loop. I'm trying to establish conditions for my boundaries.

I'm having issues establishing conditions for the right & left boundaries.

I've kept my code simple since my concern is the "if conditions". I've attached a photo to make it clearer.

I guess I'm confused on the difference between = and ==.

I'm trying to make the counter jump from 1,16,31,46,etc.

according to Matlab documentation it should be i = 1:Imax:Imax*Jmax.

But when I use this I get an error Incorrect use of '=' operator. To assign a value to a variable, use '='. To compare values for equality, use

'=='.

Please advise. Thanking you in advance.

Imax = 15;
Jmax = 15;

for i=1:Imax*Jmax     % Lower Boudary  (It works)  
    if i <= Imax
        C(i) = 0;
    else 
        C(i) = 1;
    end
    if i = 1:Imax:Imax*Jmax    % Left Boundary (Doesn't work)
        D(i) = 0;
    else 
        D(i) = 1;
    end 
    if i = Imax:Imax:Imax*Jmax   % Right Boudary (Doesn't work)
        F(i) = 0;
    else 
        F(i) = 1;
    end
    if i > (Imax*Jmax)-Imax    % Upper Boundary (It works)
        G(i) = 0;
    else 
        G(i) = 1;
    end
end

[Sugar Daddy]

if i = Imax:Imax:Imax*Jmax 

this syntax is for for loop.

Answer 1

[Cris LaPierre]

I guess I'm confused on the difference between = and ==.

One equals means 'set equal to or assign'. x=5 assign x a value of 5.

Two equals is for comparing two values for equality. x==5 checks if the value of x is 5. If it is, the output is 1, otherwise it is 0.

How do I change the increment in an if statement inside a loop

If statements do not loop. They execute based on the result of a conditional statement. That condition must return a single logical value. Typically, these conditional statements use <,<=,==,>=, or >, but never =. Place this inside a loop (for/while) to check multiple conditions, where each loop checks a single condition.

If you want to check if your variable is one of multple possibilities, use the ismember function.

if ismember(i,1:Imax:Imax*Jmax)
    ...
end