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Topic: piecewise-linear approximation
Replies: 3   Last Post: Jul 12, 2013 9:51 AM

 Messages: [ Previous | Next ]
 William Elliot Posts: 2,637 Registered: 1/8/12
Re: piecewise-linear approximation
Posted: Jul 11, 2013 3:02 AM

On Wed, 10 Jul 2013, onn1.reo@gmail.com wrote:

> I am trying to come up with an algorithm. I know I am making this harder
> than is/should be. I have multiple data sets that look alot like the
> example below:

> if {X} > .09 then Y= +3
> if .10 < {X} > .13 then Y= +1.5
> if .14 < {X} > .19 then Y= +0
> if .20 < {X} > .26 then Y= -.5
> if .27 < {X} > .33 then Y= -1.5
> if .33 < {X} then Y= -2
>
> which would yields a "stair step" graph.

What the heck does .27 < {X} > .33 mean?

> MY QUESTION:

> How do I turn this -very discrete- and clumsy function I have right now into
> something more continuous and elegant?

> Is a polynomial interpolation the only appropriate method for something this basic?

> My equation doesnt have to hit all the data points (obviously it can't), but
> I would like something with tighter intervals that is more continuous
> without having to go in manually and break everything down further and
> further ( I have several dozen of the rules shown above, all with different
> values).

Date Subject Author
7/10/13 onn1.reo@gmail.com
7/11/13 William Elliot
7/11/13 onn1.reo@gmail.com
7/12/13 Peter Percival