How to connect points on a Matlab plot? - matlab

Question

I wrote the code to get the relationship between the two variables. The code is as follows:
for fn=0.1:0.1:10
for Qe= [0.1,0.5, 1, 5]
fn2=fn.*fn;
Mg=abs((Ln*fn2)/(((Ln+1)*(fn2)-1)+1i*(((fn2)-1).*fn.*Qe*Ln)));
semilogx(fn,Mg,'b','linewidth',7);
hold on;
save;
end
end
However, The curves I got are scatters points. I want to get all points to be connected. When I increase the step point for fn, i.e fn=0.1:0.001:10, it is better, but it takes a very long time.

Answer 1

Your problem is that you plot a single point every iteration. Let the loops run their course, save the points as vectors, then call a single plot at the end plotting the vectors, which will automatically generate connected lines.
fn=0.1:0.1:10
Qe= [0.1,0.5, 1, 5]
Mg = zeros(numel(fn),numel(Qe)); %initialise output
for ii=1:numel(fn)
fn2=fn(ii)^2;
for jj = 1:numel(Qe)
Mg(ii,jj)=abs((Ln*fn2)/(((Ln+1)*(fn2)-1)+1i*(((fn2)-1).*fn(ii).*Qe(jj)*Ln))); %save in matrix form
end
end
figure
hold on;
semilogx(fn,Mg(:,1),'b','linewidth',7); % Generate plots with different colours
semilogx(fn,Mg(:,2),'r','linewidth',7);
semilogx(fn,Mg(:,3),'y','linewidth',7);
semilogx(fn,Mg(:,4),'g','linewidth',7);

Answer 2

I could solve it using this code. It could solve the problem, however, it is a little bit slow (
%%Parameters%%
Ln=8;
Mgmin=0.88;
Mgmax=1.18;
Qe= [0.25,0.3,0.35,0.7,1.65,4,8];
c= {'b','m','r','g','y','c','k'};
%%Gain Vs Frequecny Function%%
fn=0.1:0.001:10;
fn2=fn.*fn;
%%Gain Curve%%
figure;
for j=1:7
for i=1:9901
Mg(i)=abs((Ln*(fn2(i)))/(((Ln+1)*(fn2(i))-1)+1i*(((fn2(i))-1).*fn(i).*Qe(j)*Ln)));
end;
semilogx(fn,Mg,c{j},'linewidth',3);
hold on;
plot(fn,Mgmax,'k');
hold on;
plot(fn,Mgmin,'k');
save;
end;