plot a graph using For statement

Hi, I wonder if anyone can help.

I want to plot a function called mag(m2,1) from x-axis 10 to 500 but i want to simplify the code so that i dont have to rewrite cases where m and n are other numbers, say m=3,n=4 ; m=1,5 etc, generally for m=1 to 5 and n=1 to 5, for codes below, i only put 2 cases where m=1 n=1 and m=1 n=2. At the end i want to add all the plot of m=1..5, n=1..5.

for num2 = 10:500

f=1e-10+(num2-1);         

Freq(num2,1)=f;

coef_HFv=a;  

       for m=1
          for n=1
                HHFv1=HHFv1+sin(m*n);
          end
       end
                HFv1(num2)=coef_HFv*HHFv1;

      for m=1
          for n=2
                HHFv2=HHFv2+sin(m*n);
          end
       end
                HFv2(num2)=coef_HFv*HHFv2;

end

mag=zeros(491,1);

for m2=10:500

      mag(m2,1)=log10(HFv1(m2))+log10(HFv2(m2));

end

figure(1)
plot(Freq(10:500,1), mag(10:500,1), 'LineWidth',2);
grid on

[Youssef Khmou]

Define all the variables you have to test the code, a, HHFv1 , etc,

[Eric Truslow]

Actually, your code should not work since you have not initialized HHFv1 to a value:

    HHFv1=HHFv1+sin(m*n)

Is this sum important?

[Youssef Khmou]

where is the variable a, and as you want m and n from 1to 5 then HHFv1 and HHFv2 are the same and are equal .

Answer 1

[Youssef Khmou]

Hi,you have to define all your variables , the code now is technically correct but you have to initialize your variables :

 for num2 = 10:500

 f=1e-10+(num2-1);         

 Freq(num2)=f;

 coef_HFv=3; % you put here a  , to me  a is unknown   
 HHFv1=0; HHFv2=0;

       for m=1:5
          for n=1:5
                HHFv1=HHFv1+sin(m*n);
                HHFv2=HHFv2+sin(m*n);
          end
       end
                HFv1(num2)=coef_HFv*HHFv1;
                HFv2(num2)=coef_HFv*HHFv2;

 end

 mag=zeros(491,1);

 for m2=10:500

      mag(m2)=log10(HFv1(m2).*HFv2(m2));

 end
mag=mag';
figure(1)
plot(Freq(10:500), mag(10:500), 'LineWidth',2);
grid on

You can replace the two loops for HHFv1 and HHFv2 by this :

G=(1:5)'*(1:5);
HHFv1=sum(sum(sin(G)));
HHFv2=HHFv1 % according to you code they are the same,