error about Euler method

Hi guys, can anyone hepl me? I have to solve two differential equations with the Euler method. They are V(i+1)=... and gamma(i+1)=...

Thanks.

The ERROR is:

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

Error in (line 56)

V(i+1)=V(i)+(((0.5*rho(i)*V(i))/(sin(gamma(i))))*B - g(i)/V(i))*Delta_H;

And the SCRIPT is:

FILE=importdata('FILE.dat',',');
H=FILE.data(:,1))*1000; % [m]
g=FILE.data(:,2); % [m/s^2]
T=FILE.data(:,3); % [K]
rho=FILE.data(:,4); % [Kg/m^3]
P=FILE.data(:,5); % [K/Kmol]
lambda=FILE.data(:,6); % [m]
R_0=6378000;
n=length(H);
V(1)=7500;        % [m/s] initial value of V
gamma(1)=convang(1.5,'deg','rad');  %initial value of gamma
for i=1:(n-1)
    Delta_H=H(i+1)-H(i);
    R=R_0+H(i);
    V(i+1)=V(i)+(((0.5*rho(i)*V(i))/(sin(gamma(i))))*B - g(i)/V(i))*Delta_H;
    gamma(i+1)=gamma(i)*+(1/(R*(sin(gamma(i)))) ...
    -((g(i)/(V(i)^2))*(1/(tan(gamma(i))))))*Delta_H;
end
gamma_deg=convang(gamma,'rad','deg'); 
figure(1)
plot(V,(H/1000),'k-','Linewidth',1.15)
figure(2)
plot(gamma_deg,(H/1000),'k-','Linewidth',1.15)

Answer 1

[Walter Roberson]

B is not defined in the code. It has whatever value is left over in the workspace.

[Antonino Tirino]

The variable "B" is defined even if it is not present here because I forgot to report it, but in the code I have executed it is present and It Is a scalare value. What could the cause of the error?

[Walter Roberson]

The cause of the error is that B is not a scalar at the time the problem occurs.

dbstop if error

run the code. When it stops examine the size of B and then the size of each of the subexpressions.

[Antonino Tirino]

I solved the cause of error. Thanks.