Unable to perform assignment because the left and right sides have a different number of elements

2 visualizaciones (últimos 30 días)
Hi everbody, in my program, i can plot S vs t, but i can not plot S vs I and i take the erros 'Unable to perform assignment because the left and right sides have a different number of elements'. to solution this problem very important for me. thanks in advance.
step=0.0005e-9;
t=(0:step:50e-9)';
a=length(t);
I=linspace(0,10e-3,a)';
Nw=zeros(a,1);
Ng=zeros(a,1);
S=zeros(a,1);
Pout=zeros(a,1);
Alfa_m=(log(1/(R1*R2)))/(2*Length*Nr);
Pcon=((Vg*h*Va*Alfa_m*c)/(Lamda*Gamma));
fNw=@(t,Nw,Ng) ((I./(q*Va))-(Nw./twg)-(Nw./twr)+(Ng./tgw));
fNg=@(t,Nw,Ng,S) ((Nw./twg)-(Ng./tgw)-(Ng./tr)-Gamma*Vg*Alfa.*(Ng-Nb).*S);
fS=@(t,Ng,S) (Gamma*Vg*Alfa.*(Ng-Nb).*S)-(S./tp)+(Beta.*(Ng./tr));
for i=1:a-1
k1=fNw(t(i),Nw(i),Ng(i));
m1=fNg(t(i),Nw(i),Ng(i),S(i));
n1=fS(t(i),Ng(i),S(i));
k2=fNw(t(i)+step/2,Nw(i)+step/2*k1,Ng(i)+step/2*m1);
m2=fNg(t(i)+step/2,Nw(i)+step/2*k1,Ng(i)+step/2*m1,S(i)+step/2*n1);
n2=fS(t(i)+step/2,Ng(i)+step/2*m1,S(i)+step/2*n1);
k3=fNw(t(i)+step/2,Nw(i)+step/2*k2,Ng(i)+step/2*m2);
m3=fNg(t(i)+step/2,Nw(i)+step/2*k2,Ng(i)+step/2*m2,S(i)+step/2*n2);
n3=fS(t(i)+step/2,Ng(i)+step/2*m2,S(i)+step/2*n2);
k4=fNw(t(i)+step,Nw(i)+step*k3,Ng(i)+step*m3);
m4=fNg(t(i)+step,Nw(i)+step*k3,Ng(i)+step*m3,S(i)+step*n3);
n4=fS(t(i)+step,Ng(i)+step*m3,S(i)+step*n3);
Nw(i+1)=Nw(i)+step/6*(k1+2*k2+2*k3+k4);
Ng(i+1)=Ng(i)+step/6*(m1+2*m2+2*m3+m4);
S(i+1)=S(i)+step/6*(n1+2*n2+2*n3+n4);
end
plot(I,S);

Respuesta aceptada

Dana
Dana el 18 de Sept. de 2020
Your varibles k1, k2, k3, and k4 are vectors, so when you do the line near the bottom of your loop
Nw(i+1)=Nw(i)+step/6*(k1+2*k2+2*k3+k4);
the right-hand side evaluates to a vector of the same length as the k's, which you're trying to assign to a single element of Nw. Hence the error. I think you'll have a similar problem with the next two lines after that one as well.
  7 comentarios
Dana
Dana el 18 de Sept. de 2020
Vefa, you didn't address a single one of the specific issues I raised in my previous post. Why did you include t as an argument to a function but then never use t in that function? Why are you using a vector I in a function when you're expecting that function to output a scalar (or is that even the case)?
Erkan
Erkan el 18 de Sept. de 2020
Also, this dif. euations are derived according to t (time). for example dy/dt=a.y+b/y

Iniciar sesión para comentar.

Más respuestas (0)

Categorías

Más información sobre Logical en Help Center y File Exchange.

Etiquetas

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by