Math Is Fun Forum

mateobus

Member

Registered: 2008-02-11

Posts: 1

Mapping a function based on some data

I have some real data, basically several x and y coordinates. I am trying to come up with a formula for the data, but I am not sure where to begin. Based on looking at a graph, the data seems to be a polynomial, more specifially a power of two or three. Is there a piece of software that can guess a function based on the data? Any help is appreciated.

LuisRodg

Real Member

Registered: 2007-10-23

Posts: 322

Re: Mapping a function based on some data

I think the TI-XXs does that. You plug in several coordinates and it gives you a formula which is a real close estimation.

We did something like this back in High School in my IB Math Analysis class but I forgot

Im sure a program like Mathematica etc can do this. Just read their FAQ.

Last edited by LuisRodg (2008-02-11 05:22:48)

Ricky

Moderator

Registered: 2005-12-04

Posts: 3,791

Re: Mapping a function based on some data

You're going to want to store the data into lists on your TI.  How you do so depends on what TI you have.

For Ti-83, you need to use the L1, L2, ..., L6 as your lists.
For Ti above 83, you can (most likely) use any variable you want.

The format is:

variable name -> {data1, data2, data3}

Note that -> is the STO key (store).

Now put x's into one list, y's into another.  Hit the Y= button to graph, and you should see an option for plot.  On the 83, just scroll up.  On the Ti-89, you have to go into the menu.  Now enter the name of your list for the x's, name for the y, and hit enter when you're all done.  Note the nice little options you have for how you want your plot to look like.

On any version, when you graph, you can choose the option "Zoom plot".  On the 83, this is under F4.  On the 89, it's in the menu.

Is it bad that I could recall all of this without taking on look at either of these calculators?

---

"In the real world, this would be a problem.  But in mathematics, we can just define a place where this problem doesn't exist.  So we'll go ahead and do that now..."

mateobus

Member

Registered: 2008-02-11

Posts: 1

Re: Mapping a function based on some data

haha, thanks so much for the help, im digging the TI 83 out of the closet as we speak