if time is so small in series so how plot the figure

a(1)=1;
b(1)=1;
c(1)=1;
s1=0;
s2=0;
s3=0;
k3=2.8;
k1=0.33;
k2=1;
T=0.1;
t=0:0.01:0.1;
tau=0:0.1:1
tau=zeros(length(t));

for i=1:20
    a(i+1)=(1/(i+1)).*(b(i)-a(i))*k2;
     b(i+1)=(1/(i+1)).*(a(i).*(k3-c(i))-b(i));
      c(i+1)=(1/(i+1))*(a(i).*b(i)-k1*c(i));
      
   
      s1=s1+(a(i).*tau.^i);
      s2=s2+(b(i).*tau.^i);
       s3=s3+(c(i).*tau.^i); 
      disp([s1 s2 s3])
end
tau=0:0.1:1;

so how to plot the graph between tau =t/T where range of tau will be 0 to 1 ie tau=[0 1]; so the range of t=0 to 0.1

so pl plot the graph between plot(t,s1,t,s2,t,s3)

Answer 1

[Walter Roberson]

a(1)=1;
b(1)=1;
c(1)=1;
s1=0;
s2=0;
s3=0;
k3=2.8;
k1=0.33;
k2=1;
T=0.1;
t=0:0.01:0.1;
tau = t ./ T;
%tau=zeros(length(t));

for i=1:20
    a(i+1)=(1/(i+1)).*(b(i)-a(i))*k2;
     b(i+1)=(1/(i+1)).*(a(i).*(k3-c(i))-b(i));
      c(i+1)=(1/(i+1))*(a(i).*b(i)-k1*c(i));
      
   
      s1=s1+(a(i).*tau.^i);
      s2=s2+(b(i).*tau.^i);
       s3=s3+(c(i).*tau.^i); 
      disp([s1;s2;s3])
end

         0    0.1000    0.2000    0.3000    0.4000    0.5000    0.6000    0.7000    0.8000    0.9000    1.0000
         0    0.1000    0.2000    0.3000    0.4000    0.5000    0.6000    0.7000    0.8000    0.9000    1.0000
         0    0.1000    0.2000    0.3000    0.4000    0.5000    0.6000    0.7000    0.8000    0.9000    1.0000

         0    0.1000    0.2000    0.3000    0.4000    0.5000    0.6000    0.7000    0.8000    0.9000    1.0000
         0    0.1040    0.2160    0.3360    0.4640    0.6000    0.7440    0.8960    1.0560    1.2240    1.4000
         0    0.1033    0.2134    0.3301    0.4536    0.5837    0.7206    0.8642    1.0144    1.1713    1.3350

         0    0.1001    0.2011    0.3036    0.4085    0.5167    0.6288    0.7457    0.8683    0.9972    1.1333
         0    0.1039    0.2149    0.3324    0.4555    0.5833    0.7152    0.8503    0.9877    1.1268    1.2667
         0    0.1033    0.2131    0.3292    0.4512    0.5791    0.7126    0.8515    0.9955    1.1445    1.2981

         0    0.1001    0.2010    0.3031    0.4068    0.5125    0.6202    0.7297    0.8410    0.9535    1.0667
         0    0.1039    0.2151    0.3334    0.4587    0.5913    0.7318    0.8810    1.0401    1.2107    1.3946
         0    0.1033    0.2131    0.3291    0.4512    0.5791    0.7125    0.8512    0.9950    1.1436    1.2967

         0    0.1001    0.2010    0.3032    0.4072    0.5137    0.6232    0.7363    0.8537    0.9764    1.1056
         0    0.1039    0.2151    0.3333    0.4581    0.5894    0.7269    0.8704    1.0195    1.1736    1.3316
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9944    1.1426    1.2951

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6224    0.7343    0.8493    0.9674    1.0886
         0    0.1039    0.2151    0.3333    0.4582    0.5898    0.7282    0.8738    1.0270    1.1888    1.3603
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6226    0.7348    0.8506    0.9705    1.0951
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7279    0.8729    1.0247    1.1836    1.3494
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9696    1.0929
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8731    1.0253    1.1851    1.3530
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8504    0.9698    1.0936
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1847    1.3520
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9698    1.0934
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1848    1.3523
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9698    1.0935
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1848    1.3522
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9698    1.0935
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1848    1.3522
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9698    1.0935
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1848    1.3522
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9698    1.0935
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1848    1.3522
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9698    1.0935
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1848    1.3522
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9698    1.0935
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1848    1.3522
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9698    1.0935
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1848    1.3522
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9698    1.0935
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1848    1.3522
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9698    1.0935
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1848    1.3522
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

         0    0.1001    0.2010    0.3031    0.4072    0.5135    0.6225    0.7347    0.8503    0.9698    1.0935
         0    0.1039    0.2151    0.3333    0.4582    0.5897    0.7280    0.8730    1.0252    1.1848    1.3522
         0    0.1033    0.2131    0.3291    0.4512    0.5790    0.7123    0.8509    0.9943    1.1424    1.2948

plot(t, s1, t, s2, t, s3)

[shiv gaur]

a(1)=0;
b(1)=1;
c(1)=0;
s1=0;
s2=0;
s3=0;
k3=28;
k1=8/3;
k2=10;
T=0.1;
t=0:0.01:1;
tau = t ./ T;
%tau=zeros(length(t));
for i=1:20
    a(i+1)=(1/(i+1)).*(b(i)-a(i))*k2;
    b(i+1)=(1/(i+1)).*(a(i).*T*(k3-c(i))-b(i));
    c(i+1)=(1/(i+1))*(T*a(i).*b(i)-k1*c(i));
end
for i=1:20   
    
    s1=s1+(a(i).*tau.^i);
    s2=s2+(b(i).*tau.^i);
    s3=s3+(c(i).*tau.^i); 
    disp([s1;s2;s3])
end

plot(tau, s1, tau, s2, tau, s3)

sir at value changing is giving

Inf Inf Inf Inf Inf Inf

NaN NaN NaN NaN NaN NaN

NaN NaN NaN NaN NaN NaN

pl help to resolve the problem

[shiv gaur]

sir you are req to resolve this problem

[Walter Roberson]

I have been up all night, and I am feeling ill. I will not be resolving this problem.

[Steven Lord]

shiv gaur, looking at your question history you've been asking a lot of questions that could probably be solved if you knew how to use the debugging tools included in MATLAB. In this particular situation I recommend using an error breakpoint to pause execution when MATLAB generates a NaN or Inf value and then look at the operation you performed on that line and the data on which you performed that operation. Determine if that data matches what you expect it to be. If it does not, rerun your code with other standard, conditional, and/or error breakpoints set at earlier points to determine where the problem started.

If you haven't already taken them perhaps the MATLAB Onramp and/or MATLAB Fundamentals courses on the tutorials page would give you a good foundation of MATLAB knowledge.

[Walter Roberson]

Your values are exploding.

The graphs show log10 of the absolute values. (The values are alternating signs in practice.)

Notice that the values are headed up past 10^200. At i = 18 b and c both become infinite (that is, they overflow.)

format long g
a(1)=0;
b(1)=1;
c(1)=0;
s1=0;
s2=0;
s3=0;
k3=28;
k1=8/3;
k2=10;
T=0.1;
t=0:0.01:1;
tau = t ./ T;
%tau=zeros(length(t));
for i=1:20
    a(i+1)=(1/(i+1)).*(b(i)-a(i))*k2;
    b(i+1)=(1/(i+1)).*(a(i).*T*(k3-c(i))-b(i));
    c(i+1)=(1/(i+1))*(T*a(i).*b(i)-k1*c(i));
    if ~all(isfinite([a,b,c]),'all')
      subplot(3,1,1); plot(abs(log10(a))); title('log10(abs(a))')
      subplot(3,1,2); plot(abs(log10(b))); title('log10(abs(b))');
      subplot(3,1,3); plot(abs(log10(c))); title('log10(abs(c))');
      disp(a)
      disp(b)
      disp(c)
      error('first loop broke at i = %d', i);
    end
end

  Columns 1 through 8

                         0                         5         -18.3333333333333          57.9166666666667         -143.993055555556          302.906732253086         -589.673053242846          1361.77375688499

  Columns 9 through 16

          -5443.7221870296          59759.4445958811         -2657740.90196883          1334719063.94102         -26494588512488.9      2.59714098213512e+20     -4.46136840954973e+31      7.44623873661128e+49

  Columns 17 through 19

     -1.90047778234547e+79       8.083893319598e+126    -7.86387214278258e+203

  Columns 1 through 8

                         1                      -0.5          4.83333333333333         -14.0798611111111          37.7509837962963         -109.864405016906          499.745952265149         -3537.57621144164

  Columns 9 through 16

          54315.7224088515         -2863755.54756983          1599005135.82725         -34441630347171.6      3.63599711004329e+20     -6.69205261429863e+31       1.1913981978578e+50      -3.2308122299873e+79

  Columns 17 through 19

     1.45510079752764e+127    -1.49413570712869e+204                       Inf

  Columns 1 through 8

                         0                         0       -0.0833333333333333         -2.15972222222222         -15.1573206018518         -83.8614048501265         -443.462339789482         -3535.76323904447

  Columns 9 through 16

         -52478.7936446002         -2942802.68684416         -1555072420.38937         -35414165694570.3     -3.53614612870783e+20      -6.8810176616501e+31     -1.15868027327996e+50     -3.32204142694831e+79

  Columns 17 through 19

    -1.41514112809699e+127     -1.5363259648747e+204                      -Inf

first loop broke at i = 18

for i=1:20   
    
    s1=s1+(a(i).*tau.^i);
    s2=s2+(b(i).*tau.^i);
    s3=s3+(c(i).*tau.^i); 
    disp([s1;s2;s3])
    if any(any(isnan([s1,s2,s3])))
      error('second loop broke at i = %d', i);
    end
end
plot(tau, s1, tau, s2, tau, s3)

[Walter Roberson]

And your s values are over 10^300 and 10^500

format long g
a(1) = sym(0);
b(1) = sym(1);
c(1) = sym(0);
s1 = sym(0);
s2 = sym(0);
s3 = sym(0);
k3=28;
k1=8/3;
k2=10;
T=0.1;
t=0:0.01:1;
tau = t ./ T;
%tau=zeros(length(t));
for i=1:20
    a(i+1)=(1/sym(i+1)).*(b(i)-a(i))*k2;
    b(i+1)=(1/sym(i+1)).*(a(i).*T*(k3-c(i))-b(i));
    c(i+1)=(1/sym(i+1))*(T*a(i).*b(i)-k1*c(i));
    if ~all(isfinite([a,b,c]),'all')
      subplot(3,1,1); plot(abs(log10(a))); title('log10(abs(a))')
      subplot(3,1,2); plot(abs(log10(b))); title('log10(abs(b))');
      subplot(3,1,3); plot(abs(log10(c))); title('log10(abs(c))');
      disp(a)
      disp(b)
      disp(c)
      error('first loop broke at i = %d', i);
    end
end

for i=1:20   
    s1=s1+(a(i).*tau.^i);
    s2=s2+(b(i).*tau.^i);
    s3=s3+(c(i).*tau.^i); 
    if ~all(isfinite([s1,s2,s3]),'all')
      disp(s1)
      disp(s2)
      disp(s3)
      error('second loop broke at i = %d', i);
    end
end
plot(tau, s1, tau, s2, tau, s3);
title('original');
legend({'s1', 's2', 's3'});

plot(tau, log10(abs(s1)), tau, log10(abs(s2)), tau, log10(abs(s3)));
title('log10(abs(s))');
legend({'s1', 's2', 's3'});