plotting graph including sigma
显示 更早的评论
I am trying to plot this equation.
I have the values of B, omega_d, zeta, N_k and t_j is the multiples of 1.89.
Below is what I tried but the plot is weird and I can't find what's wrong.
Any comment will be helpfull. Thanks!
B_n=-5.36 ;
omega_d= 400;
zeta=29 ;
N_k=10;
sum=0;
for i=1:N_k
t_j= 1.89.*i;
sum= sum+ exp(-(zeta/2).*(t-t_j)).*(-zeta*(sin(omega_d/2.*(t-t_j)))+ omega_d.*cos(omega_d/2*(t-t_j)));
end
sum=B_n/omega_d.*sum;
t=0:10;
plot(t,sum)
2 个评论
Walter Roberson
2023-3-12
We recommend against using sum as the name of a variable, as it is very common to find that in the same code one also needs to use sum as the name of a function.
Walter Roberson
2023-3-12
t is not defined in this code.
采纳的回答
Your total is pretty large at small times, and by comparison decays to nothing. This behaviour continues, with large oscillations that dampen quickly relative to earlier values
syms t
Q = @(v) sym(v);
B_n = Q(-536)/100;
omega_d = Q(400);
zeta = Q(29);
N_k = 10;
parts = zeros(1, N_k, 'sym');
for i=1:N_k
t_j= 1.89.*i;
parts(i) = exp(-(zeta/2).*(t-t_j)).*(-zeta*(sin(omega_d/2.*(t-t_j)))+ omega_d.*cos(omega_d/2*(t-t_j)));
end
total = B_n/omega_d.*sum(parts);
fplot(total, [0 2])
fplot(total, [8 10])
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