definitions in a script must appear at the end of the file.

Hi

function dndt=imene2022(t,n,)
dndt=zeros(43,1)
%Chemin C
dndt(1)= k1*n(2)*n(32)+k15*n(5)*n(9)+k16*n(5)*n(24)...
+k33*n(4)*n(11)+k40*n(7)*n(25)...
+k72*n(2)*n(22)+k104*n(3)*n(5)+k105*n(3)*n(8)+k106*n(3)*n(23)...
+k117*n(16)*n(2)+k119*n(3)*n(33)+k122*n(11)*n(33)+k124*n(13)*n(33)...
+k130*n(20)*n(33)...
-k10*n(1)*n(22)-k13*n(1)*n(20)...
-k61*n(2)*n(1)...
-k68*n(1)*n(1)-k73*n(1)*n(25)...
-k74*n(1)*n(11)-k75*n(1)*n(21)-k76*n(1)*n(19)-k77*n(1)*n(17)...
-k118*n(1)*n(33)-k136*n(1)*n(3)...
-k139*n(1)*n(6);
%Chemin C+
dndt(2)= -k1*n(2)*n(32)-k5*n(2)*n(15)-k6*n(2)*n(27)...
-k61*n(2)*n(1)-k72*n(2)*n(22)...
-k117*n(16)*n(2)+k45*n(7)*n(11)+k73*n(1)*n(25)...
+k74*n(1)*n(11)+k75*n(1)*n(21)+k76*n(1)*n(19)...
+k77*n(1)*n(17)+k118*n(1)*n(33)+k122*n(11)*n(33);
%Chemin C-
dndt(3)= -k14*n(3)*n(22)-k104*n(3)*n(5)...
-k105*n(3)*n(8)-k106*n(3)*n(23)-k119*n(3)*n(33)...
-k136*n(1)*n(3)-k140*n(3)*n(4)-k141*n(3)*n(15)-k142*n(3)*n(7);
%Chemin O:
dndt(4)= k2*n(5)*n(32)+k10*n(1)*n(22)+k13*n(1)*n(20)...
+k14*n(3)*n(22)+k35*n(7)*n(15)+k36*n(7)*n(17)...
+k52*n(15)*n(22)...
+k53*n(15)*n(18)...
+k78*n(5)*n(9)+k80*n(5)*n(27)...
+k81*n(5)*n(15)+k85*n(6)*n(24)...
+k104*n(3)*n(5)+2*k107*n(5)*n(6)+k108*n(5)*n(16)...
+k109*n(6)*n(8)+k120*n(6)*n(33)+2*k126*n(15)*n(33)...
+k128*n(17)*n(33)+k130*n(20)*n(33)+k131*n(22)*n(33)...
-k21*n(4)*n(27)-k22*n(4)*n(27)-k23*n(4)*n(18)...
-k30*n(4)*n(19)-k31*n(4)*n(14)...
-k33*n(4)*n(11)...
-k82*n(4)*n(19)-k83*n(4)*n(21)...
-k133*n(4)*n(32)-k140*n(3)*n(4)-k143*n(4)*n(6);
%Chemin O+:
dndt(5)= k5*n(2)*n(15)+k34*n(8)*n(15)+k82*n(4)*n(19)...
+k83*n(4)*n(21)+k128*n(17)*n(33)...
-k21*n(4)*n(27)-k22*n(4)*n(27)...
-k23*n(4)*n(18)...
-k30*n(4)*n(19)-k31*n(4)*n(14)...
-k33*n(4)*n(11)...
-k82*n(4)*n(19)...
-k83*n(4)*n(21)-k133*n(4)*n(32)-k140*n(3)*n(4)...
-k143*n(4)*n(6);
%Chemin O-:
dndt(6)= k133*n(4)*n(32)...
   ........
   
...........
    
end
%constantes::
%temperature
T=17000
%constante k: recombinaison radiative
k1=2.36 *(1e-12)*(T/300)^(-0.29)*exp(17.60/T) 
k2 =3.24 *(1e-12) *(T/300)^(-0.66)
k3=3.50 *(1e-12)*(T/300)^(-0.53)* exp(3.20/T)....
    ........
    %initial
IC=10^19*ones(1,43)

[t,n]=ode45(@imene2021,[0 1e-3],IC)
plot(t,n)
end 

Error: File: imene2022.m Line: 212 Column: 1
Function definitions in a script must appear at the end of the file.
Move all statements after the "imene2022" function definition to before the first local function definition.

Answer 1

[Scott MacKenzie]

Functions defined in a script (such as imeme2022 in your script) must be positioned at the end of the script. The error message is clear enough. So, reposition these statements...

%constantes::
%temperature
T=17000
%constante k: recombinaison radiative
k1=2.36 *(1e-12)*(T/300)^(-0.29)*exp(17.60/T) 
k2 =3.24 *(1e-12) *(T/300)^(-0.66)
k3=3.50 *(1e-12)*(T/300)^(-0.53)* exp(3.20/T)....
    ........
    %initial
IC=10^19*ones(1,43)
[t,n]=ode45(@imene2021,[0 1e-3],IC)
plot(t,n)
end 

above the function definition. BTW, the last line above is a dangling end statement and should be removed.

[Imene Yed]

So I have to put my constantes k before function dndt=imene2022(t,n)???

thanks for your answer