## code for finding band depth of a parabola which is going from three points (7.8 0.96), (8.25 0.99) and (8.55 0.94)?

### S (view profile)

on 1 Apr 2013

how can I write code for finding band depth of a parabola which is going from three points (7.8 0.96), (8.25 0.99) and (8.55 0.94)?

## Products

No products are associated with this question.

### Image Analyst (view profile)

on 1 Apr 2013

You can get the coefficients of the formula using polyfit(). It's so really really easy that I shouldn't have to even give you the code. Just look at the help for polyfit(). After that just use whatever formula you have for "band depth". By the way, why did you tag this "image processing"?

S

### S (view profile)

on 2 Apr 2013

Band depth is defined as the absorption band depth, D, was defined relative to its continuum:

D = 1 - Rb/Rc

where Rc is the reflectance of the continuum at the band center, and Rb is the reflectance at the band center.

How can I compute band depth of this polyfit curve or parabola using this formula?

I thought it comes under image processing so I tagged?

how can I write code for finding band depth of a parabola which is going from three points (7.8 0.96), (8.25 0.99) and (8.55 0.94)?

In this problem x co-ordinate represents wavelengths and y co-ordinate represents emissivity(= 1-reflectance).

Image Analyst

### Image Analyst (view profile)

on 2 Apr 2013

I'm not sure what all those terms mean. If you have a parabola, the equation is y = coeffs(1)*x.^2 + coeffs(2)*x + coeffs(3). You can get coeffs from

` coeffs = polyfit(xArray, yArray, 2);`

So what is D, Rb, and Rc in terms of the coefficients?

S

### S (view profile)

on 3 Apr 2013

If simply I want to compute area of parabola form three points (7.8 0.96), (8.25 0.99) and (8.55 0.94)? How can I compute?

MATLAB and Simulink resources for Arduino, LEGO, and Raspberry Pi

### Discover what MATLAB® can do for your career.

Apply Today

New to MATLAB?

Learn MATLAB today!