How to use symbolic equation?

it says, 'data needs to be numeric, datetime, duration, categorical, doubled type array'

I want to plot 'gm' vs 'Ao'

Answer 1

[Star Strider]

For symbolic plots, use the fplot function —

syms Wosc R  C gm 
Ao = gm*R/(1+2*pi*Wosc*R*C);
pretty(Ao)

       R gm
-----------------
2 pi C R Wosc + 1

R = 1000;
C = 27.6E-12;
Wosc = 1E6;
Ao = subs(Ao)

Ao = 

Ao = vpa(Ao, 5)

Ao = 

figure
fplot(Ao, [1E-9, 1E-4])
grid
Ax = gca;
Ax.XScale = 'log';
xlabel('gm')
ylabel('Ao')

.

[동훈]

It was very helpful!

[Star Strider]

Thank you!

Answer 2

[Walter Roberson]

The basic problem is that subs() does not change the thing being substituted into. You would need to have Ao = subs(...)

Also, you cannot plot() a symbolic expression. You can fplot() it -- if you do then the default is to plot over the range -5 to +5, so you would want to supply the interval to fplot() over.

[동훈]

I found my self stupid :O