Variables Calculated in Function Somehow Aren't Assigned to Output

My code was working only a day ago, but it just stopped giving me output. I know it calculates the variables I need (wg,pm) becasue it will display them, but it never leaves the scope of the for loop. I know its gotta be something simple, but I'm stumped.

function[wp,pm,wg,gm] = pleaseWork(tf_in)

tf = inline(tf_in,'r')
figure

j = 1

for w = 0:0.1:100
    
    magDB = 20*log10(abs(tf(i*w)));
    phase = mod((180/pi)*atan2(imag(tf(i*w)),real(tf(i*w))),-360);
        
        if round(magDB) == 0
            wg = w
            pm = phase + 180
        end
        
        if round(phase) == -180
            wp = w
            gm = -magDB
        end
        
    hold on
    subplot(2,1,1)
    title('HW 2 #9')
    ylabel('Magnitude (dB)')
    semilogx(w,20*log10(abs(tf(i*w))),'b.')
    hold on
    subplot(2,1,2)
    ylabel('Phase (deg)')
    xlabel('Angular Frequency (rad/s)')
    semilogx(w,phase,'b.')
    j = j + 1;







end


end

[Torsten]

Before entering the for-loop, assign values to wg,pm,wp,gm (e.g. NaN).

What's the relevance of the variable j ?

[Dominic Troche]

Yeah that was it, I had no idea MATLAB wouldnt output if all outputs weren't assigned. j was accidentally copy and pasted over to this post, I truncated a lot of the code for readability.

Answer 1

[Jonas]

looks like your two if statements are never fullfilled, thats why output variables are empty

[Dominic Troche]

They're fufilled, as I can get it to display what I need while the function is executing. I just cant get it to output that value.

For example with a transfer function '50/(r*(r+1))'

[Dominic Troche]

Actually, you're 100% correct. I didnt know MATLAB would assign any outputs if ALL o them werent assigned at some point.