Plot symbolic polynomial

How to plot a symbolic expression that contains a symbol and i(imaginary).

Eg. Plot y=x^2+i+2

Answer 1

[Andrew Newell]

This plots the real part of y against x:

syms x y
ezplot(y-x^2-1i-2)

Of course, it looks just the same as

syms x y
ezplot(y-x^2-2)

EDIT: For a 3D plot, you could do this:

syms x
ezplot3(x,x^2+2,1)
xlabel('x')
ylabel('Real(y)')
zlabel('Imag(y)')

[Sukhmeet]

Yes, I do need to plot the imaginary component, if possible. Please help.

Answer 2

[Sean de Wolski]

doc ezplot

[Sukhmeet]

Not correct I guess...

I did

syms x y

y=x^2+i+2

ezplot(y)

Not coming dude.....

error--one or more output arguments not assigned during call to C:\Matlab7\toolbox\matlab\specgraph\ezplot.m(ezplot1)

Answer 3

[Susan]

I got an error with ezplot, so did this instead:

syms x y
y=x^(2+i)+2;
xx=linspace(-6,6,100);
yy=subs(y,x,xx);
plot3(xx,real(yy),imag(yy));grid
xlabel('x');ylabel('y');zlabel('z');

[Andrew Newell]

That should be

y=x^2+i+2;

Even better is

y=x^2+1i+2;

because then you don't have to worry about i being used as a variable.

What error did you get?