Problem with looping: the loop does not stop

Hello!

I have a problem that I have built a simple loop, which does not stop while running the code. Does anyone know what could be the issu? I have Matlab 2014.

Lw=106.5
hs=80
hr=1.5
a_air=0.0001
La=zeros(1,8000)
d=1:8000

for  i=1:8000
     if i<=1000
         La(i)=Lw - 8 - 20*log(i) - 0.005*i
     else
         deltaLa=10*log(10^(Lw/10)) - 10*log(10^((Lw-sqrt(i)*a_air)/10))
         La(i)=Lw - 8 - 20*log(i) - deltaLa + 10*log(i/1000)
     end  
end

Thank you!

[Muhammad Usman]

Why are you using

d=1:8000

for loop check the if condition at every iteration, and will continue for 8000 in total.

So you can skip the for loop and just use 'd' array to compute your results

Lw=106.5;
hs=80;
hr=1.5;
a_air=0.0001;
La=zeros(1,8000);
d=1:8000;
     if d<=1000
         La(d)=Lw - 8 - 20*log(d) - 0.005*d
     else
         deltaLa=10*log(10.^(Lw/10)) - 10*log(10.^((Lw-sqrt(d)*a_air)/10));
         La(d)=Lw - 8 - 20*log(d) - deltaLa + 10*log(d/1000)
     end  

Answer 1

[Jamal Nasir]

%%% you can try this it work good %%%%
clc 
clear 
Lw=106.5
hs=80
hr=1.5
a_air=0.0001
d=1:8000
La=[];
for  i=1:8000    
     if i<=1000
         La=[La; Lw - 8 - 20*log(i) - 0.005*i];
    else
         deltaLa=10*log(10^(Lw/10)) - 10*log(10^((Lw-sqrt(i)*a_air)/10))
         La=[La;Lw - 8 - 20*log(i) - deltaLa + 10*log(i/1000)];
     end  
end

[Muhammad Usman]

your logic contradicts as you first established

La=zeros(8000,1)

and then

La=[];

it means you assigned La zeros values and make it empty

[Jamal Nasir]

Delete first one

[Muhammad Usman]

What about the results produced by me in the comment section?

[Anne]

Thanks! It works :)

Why my script did not work? I just found out that I had semicolons missing, do you think it was the reason why it kept running?