Index exceeds matrix dimensions?? Error in my script..help please?

Hi everyone, I need some help. In the script (that I'll link) I get this error:

     Index exceeds matrix dimensions.

     Error in Integration (line 28)
            fi1(i+1)= fi1(i) + dt*(w-s.*N1(j)*cos(fi1(i)));

and I don't know how and why, can you help me please? Is very important..

Answer 1

[Birdman]

clear 
close all
dt=0.1;
t=(1:dt:10);
t=t(:);
N1=(0:1:99);
N2=(0:1:99);
N3=(0:1:99);
N4=(0:1:99);
n1=fliplr(N1);
n2=fliplr(N2);
n3=fliplr(N3);
n4=fliplr(N4);
w=0.04;
s=0.0052;
fi1=zeros(length(t),1);
fi2=zeros(length(t),1);
fi3=zeros(length(t),1);
fi4=zeros(length(t),1);
for i=1:length(t)-1

      for j=1:length(N1)
          if 0<fi4(i)<=pi/2
              fi1(i+1)= fi1(i) + dt*(w-s.*N1(j)*cos(fi1(i)));
          elseif pi/2<fi4(i)<=pi
              fi1(i+1)= fi1(i) + dt*(w-s.*n1(j)*cos(fi1(i)));
          end
      end

      for j=1:length(N2)
           if 0<fi1(i)<=pi/2
              fi2(i+1)= fi2(i) + dt*(w-s.*N2(j)*cos(fi2(i)));
          elseif pi/2<fi1(i)<=pi
              fi2(i+1)= fi2(i) + dt*(w-s.*n2(j)*cos(fi2(i)));
           end
      end

      for j=1:length(N4)     
            if 0<fi3(i)<=pi/2
              fi4(i+1)= fi1(i) + dt*(w-s.*N4(j)*cos(fi4(i)));
          elseif pi/2<fi3(i)<=pi
              fi4(i+1)= fi4(i) + dt*(w-s.*n4(j)*cos(fi4(i)));
            end
      end

      for j=1:length(N3)
           if 0<fi2(i)<=pi/2
              fi3(i+1)= fi3(i) + dt*(w-s.*N3(j)*cos(fi3(i)));
          elseif pi/2<fi2(i)<=pi
              fi3(i+1)= fi3(i) + dt*(w-s.*n3(j)*cos(fi3(i)));
          end
      end
  end

subplot( 2, 2, 1)
plot(t,sin(fi1(:,1)),'-o')
xlabel('time')
ylabel('sin(phi1) LF')
subplot( 2, 2, 2)
plot(t,sin(fi2(:,1)),'-.');
xlabel('time')
ylabel('sin(phi2) RF')
subplot( 2, 2, 3)
plot(t,sin(fi3(:,1)),'r-');
xlabel('time')
ylabel('sin(phi3) LH')
subplot( 2, 2, 4)
plot(t,sin(fi4(:,1)),'k--');
xlabel('time')
ylabel('sin(phi4) RH')

[Davide Mori]

Thank you soooo much! It works!

[Stephen23]

A good example of:

https://www.mathworks.com/help/matlab/matlab_prog/preallocating-arrays.html

[indhu ravi]

for i=1:length(D)

if (h_(i,T)~=D(i))

eps(T)=eps(T)+D(i,:);

end

end

please help for this code

indes exceeds matrix dimension

Answer 2

[Torsten]

You don't initialize

fi1(1)=0

Best wishes

Torsten.