how to find function from set of x,y points? (need steps)

[Catastropha]

Please ! can somebody show me the STEPS how to find a FUNCTION from a set of points x and y
step by step , pleasee ! i need this !

 

[Deleted member 4993]

Re: How do I find the function of a graph based on points?

Please ! can somebody show me the STEPS how to find a FUNCTION from a set of points x and y
step by step , pleasee ! i need this ! (please post a problem and your work - so that we know where to begin to help you)

Start a new topic (new thread) with new problem.

 

[Catastropha]

Re: How do I find the function of a graph based on points?

Look ...
I have a graph , it`s not a standart graph, i mean it`s not quadratic or something.
and i know all the coordinates X and Y

and i want to find the Function of the graph , i know one thing that the function must be aproximately it can`t be an exact function

i have no example i just need to learn how to do this

 

[stapel]

Are you supposed to find a regression equation for a set of "real life" data points? If so, what tools and techniques are available for you to use?

Are you supposed to find an exact formula for a set of "known good" plot points? If so, what tools and techniques are available for you to use?

Please be complete. Thank you!

Eliz.

 

[Catastropha]

actually i need this in programming, i want to generate a GOOD function from a list of x and y points
first i must solve it in a mathematical way.
i don`t know Techniques for solving such kind of problems that`s why i`m here, maybe smb will explain me
x and y are arbitrary ,i mean the graph is not special one

tools: for a start only papper and pencil

 

[stapel]

i want to generate a GOOD function from a list of x and y points

Just defining "good" is an entire area of mathematical study. :shock:

You seem to be under the impression that there is some one formula out there somewhere, into which any set of points can be plugged and "the right answer" returned. I'm afraid it simply doesn't work that way. The reason we've been asking for some input from you is at least in part because there are so many ways to proceed, many of them relying on different assumptions and arriving at different solutions.

If you really want to learn about this, a good place to start would be to enroll in a sequence of statistics courses at your local college or university. But people wouldn't make this a life study if the entire issue could be explained and resolved in a "fifty words or less" sort of post. Sorry.

Eliz.

 

[Catastropha]

i think that for any graph defined at any point must have a function...

why is it so difficult :?:
isn`t there an algorithm how to find that function ?

i need this for FOREX , i have the arhive about 15 years of all the graph , all i need is to know how to solve a simple graph in a mathematical way, after that the computer will find for me the function for a 15 years graph

it`s not necesarily to find the exact function

 

[stapel]

i think that for any graph defined at any point must have a function...

Um... no, I don't think so.... :shock:

why is it so difficult

The process is difficult because there are so very many different considerations which come into play, and many of the techniques are rather intensive.

isn`t there an algorithm how to find that function ?

As mentioned earlier, no, there is not one formula or algorithm that will produce "the" function for any given set of points. In fact, one could fit any number of different functions through, or near, your set.

I'm sorry, but whoever told you that regression, error analysis, polynomial fitting, etc, etc, can be "done" in a sentence or two was very much mistaken!

Eliz.

 

[Catastropha]

nobody told me nothing
an ideea came into my mind how to make some money and that`s all

if you watched PI 3.14 movie there is said that everything in the world can be expressed in numbers, you must find the SYNTAX

well... i guess i need to think for a better idea

 

[Deleted member 4993]

There are commercial softwares available - e.g. Excel, Kaliedagraph, Matlab, etc. - that can take a set of co-ordinates and fit a curve (but you need to define what the overall nature is - e.g. polynomial, logarithimic, etc.).