How can MATLAB help in finding an equation for a given curve?

[davidmandis]

Hi,
I need to find a single equation to represent the curve shown in the attached figure. I have access to MATLAB if that will help. Can anyone help me out?

Thanks,
David

 

[HallsofIvy]

What exactly do you mean by "a single equation"? That can be simply written as a "piecewise linear function": f(x)= x/2000 if x$\le$ 4000, f(x)= 2 if x> 4000.

If you want a "single expression", use the Heaviside function H(x) which is defined by "H(x)= 0 if x$\le$ 0, H(x)= 1 if x> 1". We can fit it to f by taking H(x- 4000).

f(x)= x/20000 + H(x- 4000)(4000- x/2000)

If x$\le$4000, H(x- 4000)= 0 so f(x)= 1/2000. If x> 4000, H(x- 4000)= 1 so f(x)= 1/2000+ 4000- x/2000= 4000.

 

[tacman]

Hi David,

Finding an equation for a curve can be a challenging task, but with the help of MATLAB, it can become a lot easier. First, you will need to gather some information about the curve, such as the coordinates of several points on the curve. Once you have this data, you can use MATLAB's curve fitting tools to find the best equation that fits the curve.

One way to do this is by using the "polyfit" function in MATLAB, which takes in the x and y coordinates of the points and fits a polynomial curve to them. You can also use the "fit" function, which allows you to choose from a variety of different curve fitting models, such as linear, exponential, or power functions.

Once you have found the best fitting equation, you can plot it on the same graph as your curve to see how well it matches. If you are satisfied with the fit, you can use the equation to represent the curve. If you need further assistance, there are also many online resources and tutorials available for using MATLAB's curve fitting tools.

I hope this helps you in finding the equation for your curve. Best of luck!