How to plot x=f(y) ?

I'm new in matlab.I have function Y=x^3+x^2-x+6.I want to draw graph x=f(y).I don't know how to make it.Please support for me.Thank you so much

Answer 1

[KSSV]

You have to mention x range. I am considering here 0 to 10.

x = linspace(0,10,500) ;
y=x.^3+x.^2-x+6 ;
plot(x,y)
xlabel('x')
ylabel('y')
title('y=x^3+x^2-x+6')

[John D'Errico]

Um, this does not answer the question, which was to plat the INVERSE relationship, x=f(y).

[huynh trong]

But I Have value of y.Example.Y=0:.1:100. Can I draw x=f(y)?.Thanks for your support

[KSSV]

Ohhh John D'Errico I read it as y = f(x). Thanks for pointing out. How about this?

syms x
f(x) = x^3+x^2-x+6 ;
g = finverse(f) ;

y1 = linspace(0,10) ;
x1 = subs(g,y1) ;
plot(x1,y1)

Actually range of x should be given.

Answer 2

[John D'Errico]

You wish to plot the inverse relationship, x=f(y), given the expression

y = x^3+x^2-x+6

Note that in general, this need not be a single valued function. In fact, your relationship is not:

ezplot('y=x.^3+x.^2-x+6',[-3,3],[-3,10])

So for some values of y, there are several values of x to be found. It looks like for y roughly in the interval [5,7] we will find three solutions.

I can convince ezplot to give that plot as:

ezplot('x=y.^3+y.^2-y+6',[-3,10],[-3,3])

ezplot is a bit dumb, but that is the plot you asked to see. It rather foolishly insists on putting x and y on their respective axes. We could as easily have done the work the hard way, using plot directly. But why bother?

Answer 3

[Thorsten]

Instead of plot(x,y), you plot(y,x)

x = linspace(-3,3); plot(x.^3+x.^2-x+6, x), xlabel('y'), ylabel('x')