How to Solve 13 ODEs simultaneously by ode45

        i need to solve 13 ODEs ,all are interdependent, i need to solve it using ode45 and tgen plot it but the error is it says index is more than 12
        Any help on this is highly appreciated.

       qgin=12;
    c_g_in=[1 2 3 4 5 6 ];
    c=zeros(13,1);
    c_l_in=[1 3 5 7 3 5 ];
    vg=27;
    kla=[13 34 5 6 7 7 ];
    vl=65;
    m=[23 3 5 2 1 4];
    ql=123;
    v_max=[1 2 3 5 7 1];
    for i=1:6
        v(i)=-v_max(i).*c(i);
    end
    xp=45;
    yxco=12;
    yxh2=5;
    mu=-v(1)*yxco-v(2)*yxh2;
    kd=15;
    c0=[1 2 3 0 0 0 0 0 0 2 5 6 13];
    c0g=c0(1:6);
    ngout=qgin*sum(c_g_in,'all')-kla(1)*((c(1)/m(1))-c(7))*vl-kla(2)*((c(2)/m(2))-c(8))*vl-kla(3)*((c(3)/m(3))-c(9))*vl+kla(4)*((c(10)/m(4))-c(4))*vl+kla(5)*((c(11)/m(5))-c(5))*vl+kla(6)*((c(12)/m(6))-c(6))*vl;
    qgout=ngout*R*t/(sum((psat.*c0g),'all'));
    f=@(t,c)[((qgin.*c_g_in(1)-qgout.*c(1))./vg)-kla(1).*(vl/vg).*((c(1)./m(1))-c(7)), 
            ((qgin.*c_g_in(2)-qgout.*c(2))./vg)-kla(2).*(vl/vg).*((c(2)./m(2))-c(8)),
             ((qgin.*c_g_in(3)-qgout.*c(3))./vg)-kla(3).*(vl/vg).*((c(3)./m(3))-c(9)),
            ((qgin.*c_g_in(4)-qgout.*c(4))/vg)+kla(4).*(vl/vg).*((c(10)./m(4))-c(4)),
            ((qgin.*c_g_in(5)-qgout.*c(5))/vg)+kla(5).*(vl/vg).*((c(11)./m(5))-c(5)),
            ((qgin.*c_g_in(6)-qgout.*c(6))/vg)+kla(6).*(vl/vg).*((c(12)./m(6))-c(6)),
            ((ql/vl).*(c_l_in(1)-c(7))+kla(1).*((c(1)./m(1))-c(7))+v(1).*c(13)),
            ((ql/vl).*(c_l_in(2)-c(8))+kla(2).*((c(2)./m(2))-c(8))+v(2).*c(13)),
            ((ql/vl).*(c_l_in(3)-c(9))+kla(3).*((c(3)./m(3))-c(9))+v(3).*c(13)),
            ((ql/vl).*(c_l_in(4)-c(10))-kla(4).*((c(10)./m(4))-c(4))+v(4).*c(13)),
            ((ql/vl).*(c_l_in(5)-c(11))-kla(5).*((c(11)./m(5))-c(5))+v(5).*c(13)),
            ((ql/vl).*(c_l_in(6)-c(12))-kla(6).*((c(12)./m(6))-c(6))+v(6).*c(13)),
            ((ql/vl).*(-c(13).*xp)+mu.*c(13)-kd.*c(13))]
    tspan=[0 600];
    [t,c]=ode45(f,tspan,c0);

error is as follows

f =

    function_handle with value:

      @(t,c)[((qgin.*c_g_in(1)-qgout.*c(1))./vg)-kla(1).*(vl/vg).*((c(1)./m(1))-c(7));((qgin.*c_g_in(2)-qgout.*c(2))./vg)-kla(2).*(vl/vg).*((c(2)./m(2))-c(8));((qgin.*c_g_in(3)-qgout.*c(3))./vg)-kla(3).*(vl/vg).*((c(3)./m(3))-c(9));((qgin.*c_g_in(4)-qgout.*c(4))/vg)+kla(4).*(vl/vg).*((c(10)./m(4))-c(4));((qgin.*c_g_in(5)-qgout.*c(5))/vg)+kla(5).*(vl/vg).*((c(11)./m(5))-c(5));((qgin.*c_g_in(6)-qgout.*c(6))/vg)+kla(6).*(vl/vg).*((c(12)./m(6))-c(6));((ql/vl).*(c_l_in(1)-c(7))+kla(1).*((c(1)./m(1))-c(7))+v(1).*c(13));((ql/vl).*(c_l_in(2)-c(8))+kla(2).*((c(2)./m(2))-c(8))+v(2).*c(13));((ql/vl).*(c_l_in(3)-c(9))+kla(3).*((c(3)./m(3))-c(9))+v(3).*c(13));((ql/vl).*(c_l_in(4)-c(10))-kla(4).*((c(10)./m(4))-c(4))+v(4).*c(13));((ql/vl).*(c_l_in(5)-c(11))-kla(5).*((c(11)./m(5))-c(5))+v(5).*c(13));((ql/vl).*(c_l_in(6)-c(12))-kla(6).*((c(12)./m(6))-c(6))+v(6).*c(13));((ql/vl).*(-c(13).*xp)+mu.*c(13)-kd.*c(13))]

Error using odearguments (line 113)
Inputs must be floats, namely single or
double.

Error in ode45 (line 115)
  odearguments(FcnHandlesUsed,
  solver_name, ode, tspan, y0, options,
  varargin);

Error in gshs (line 36)
[t,c]=ode45(f,tspan,c0);

[James Tursa]

Please format your code so that it is readable. Also copy & paste the entire error message for us to read, including the offending line.

[Sumeet Sinha]

thank you james for pointing out,was helpful but the problem of unable to solve 13odes still remains after the correction

Answer 1

[James Tursa]

Your c0 has only 12 elements. It needs to have 13 elements.

[Sumeet Sinha]

after the correction the problem.remains.kindly assist me in this

[James Tursa]

Can you post your current code? What are yxco and yxh2? Everything in your derivative function needs to be numeric. Do you have symbolic variables anywhere?

[Sumeet Sinha]

please assume any variable.other than c to be numeric.you can assign it any value.

[James Tursa]

Most contributors here don't like to make assumptions about code ... especially when the entire code isn't shown and there are errors involved. We prefer to copy & run complete code that reproduces the error so that we can decipher for sure what is causing the error.

[Sumeet Sinha]

i have been trying to solve this code for past 12 hrs but unable to point out the error evenafter replacing all constants with its trailing zero

below is the code changing integer to float

qgin=12.000;
c_g_in=[1.000 2.000 3.000 4.000 5.000 6.000 ];
c=zeros(13,1);
c_l_in=[1.000 3.000 5.000 7.000 3.000 5.000];
vg=27.000;
kla=[13.000 34.000 5.000 6.000 7.000 7.000 ];
vl=65.000;
m=[23.000 3.000 5.000 2.000 1.000 4.000];
ql=123.000;
v_max=[1.000 2.000 3.000 5.000 7.000 1.000];
for i=1:6
    v(i)=-v_max(i).*c(i);
end
xp=45.000;
yxco=3.000;
yxh2=5.000;
mu=-v(1)*yxco-v(2)*yxh2;
kd=15.000;
c0=[1.000 2.000 3.000 0.000 0.000 0.000 0.000 0.000 0.000 2.000 5.000 6.000 13.000];
c0g=c0(1:6);