Error Using Plot for single variable function

I am trying to plot the function Rv(f) and then theta(f). However, whenever I run it I get "Error using plot

Data must be numeric, datetime, duration or an array convertible to double."

Any help would be appreciated.

syms   f
% Physical properties of the bar

V0 = 1;
R = 1000;
L = 470*10^(-6);
C = 120*10^(-12);

Rv(f) = (V0*R)/sqrt(R^(2)+(2*pi*f*L-1/(2*pi*f*C))^(2));
theta(f) = atan(((1/(2*pi*f*C))-2*pi*f*L)/R);

x1 = 0:1000:4000000;
% Calculate the inital distribution (almost)

plot(x1,Rv(f))
    xlabel('x');
    grid on
    grid minor
    pause(0.01)

[KSSV]

Youcannot use Rv(f) which is a function striaght away in plot. Substitute the values of f using subs and plot.

[Preston Glenn]

could you show how to use subs in this case. not quite getting it still. I'm trying

subs(Rv,f,x1);

Answer 1

[Ameer Hamza]

There are two ways.

1. use fplot

syms   f
% Physical properties of the bar
V0 = 1;
R = 1000;
L = 470*10^(-6);
C = 120*10^(-12);
Rv(f) = (V0*R)/sqrt(R^(2)+(2*pi*f*L-1/(2*pi*f*C))^(2));
theta(f) = atan(((1/(2*pi*f*C))-2*pi*f*L)/R);
x1 = 0:1000:4000000;
% Calculate the inital distribution (almost)
fplot(Rv(f), [0 4000000])
xlabel('x');
grid on
grid minor
pause(0.01)

2. using function handle

syms   f
% Physical properties of the bar
V0 = 1;
R = 1000;
L = 470*10^(-6);
C = 120*10^(-12);
Rv(f) = (V0*R)/sqrt(R^(2)+(2*pi*f*L-1/(2*pi*f*C))^(2));
theta(f) = atan(((1/(2*pi*f*C))-2*pi*f*L)/R);
x1 = 0:1000:4000000;
Rvf = matlabFunction(Rv);
% Calculate the inital distribution (almost)
plot(x1,Rvf(x1))
xlabel('x');
grid on
grid minor
pause(0.01)