Equation for half-max contour of 2D Gaussian?

In summary, the conversation is about finding the equation for the elliptical contour line at the half-max of a Gaussian function with varying parameters. The solution is h/2 = (x-x0)^2/a + (y-y0)^2/b = ln2.
  • #1
mikeph
1,235
18
Hi all,

If I have a Gaussian with the equation:

G(x,y) = h*exp(-(x-x0)^2/a -(y-y0)^2/b)

where x0, y0, a, b and h are the parameters which may vary, what's the equation for the elliptical contour line at the half-max of G?

I'm getting myself confused!

Thanks for help
 
Mathematics news on Phys.org
  • #2
MikeyW said:
G(x,y) = h*exp(-(x-x0)^2/a -(y-y0)^2/b)
what's the equation for the elliptical contour line at the half-max of G?
How far did you get? Did you find the max value? Did you plug half that into the equation to see what resulted?
 
  • #3
I was wondering if there is some standard result that meant I didn't have to do all that.
 
  • #4
MikeyW said:
Hi all,

If I have a Gaussian with the equation:

G(x,y) = h*exp(-(x-x0)^2/a -(y-y0)^2/b)

where x0, y0, a, b and h are the parameters which may vary, what's the equation for the elliptical contour line at the half-max of G?

I'm getting myself confused!

Thanks for help
G(x,y) = h/2 is what you want.

(x-x0)2/a + (y-y0)2/b = ln2.
 
  • #5
!

The equation for the half-max contour of a 2D Gaussian can be expressed as follows:

(x-x0)^2/a + (y-y0)^2/b = ln(2*h)

This equation represents the elliptical contour line where the Gaussian function has a value that is half of its maximum value (h). The parameters x0 and y0 represent the center of the Gaussian, while a and b control the spread of the Gaussian in the x and y directions, respectively. This equation can be used to plot the half-max contour of the Gaussian and visualize its shape. I hope this helps to clarify any confusion.
 

What is the equation for the half-max contour of a 2D Gaussian?

The equation for the half-max contour of a 2D Gaussian is given by:
x2 + y2 = 2σ2ln(2)

What does the half-max contour of a 2D Gaussian represent?

The half-max contour of a 2D Gaussian represents the points at which the Gaussian function reaches half of its maximum value. It essentially outlines the shape of the Gaussian curve.

How is the half-max contour of a 2D Gaussian related to the standard deviation (σ)?

The half-max contour of a 2D Gaussian is directly related to the standard deviation (σ) of the Gaussian curve. In fact, the half-max contour is equal to √(2σ2ln(2)), which is approximately 1.1774 times the standard deviation.

Can the equation for the half-max contour of a 2D Gaussian be used for any Gaussian function?

Yes, the equation for the half-max contour of a 2D Gaussian can be used for any Gaussian function, as long as it is in the form of a 2D Gaussian (i.e. in the form of x2 + y2 in the exponent).

How does the half-max contour of a 2D Gaussian change with different values of σ?

The half-max contour of a 2D Gaussian will change in size and shape as the value of σ changes. A larger σ will result in a wider half-max contour, while a smaller σ will result in a narrower half-max contour.

Similar threads

  • General Math
Replies
3
Views
1K
Replies
1
Views
749
  • Programming and Computer Science
Replies
1
Views
2K
  • High Energy, Nuclear, Particle Physics
Replies
2
Views
327
  • Programming and Computer Science
Replies
2
Views
720
  • Programming and Computer Science
Replies
9
Views
4K
  • Calculus and Beyond Homework Help
2
Replies
68
Views
4K
Replies
3
Views
1K
  • MATLAB, Maple, Mathematica, LaTeX
Replies
18
Views
3K
Replies
1
Views
1K
Back
Top