Dec 182017

POLY Ver 3.60 fits a polynomial or rational polynomials to a set of data. | |||
---|---|---|---|

File Name | File Size | Zip Size | Zip Type |

POLY.DAT | 128 | 35 | deflated |

POLY.DOC | 3109 | 1339 | deflated |

POLY.EXE | 83075 | 43808 | deflated |

# Download File POLY360.ZIP Here

## Contents of the POLY.DOC file

.ft e

.sp 1

.in 10

.de

Gentle User,

POLY is a program that allows you to fit a curve to a set of data points.

POLY can fit normal polynomials like:

Y=C1+C2*X+C3*X**2+C4*X**3+...

or rational polynomials like:

Y=(P1+P2*X+P3*X**2+P4*X**3+...)/(Q1+Q2*X+Q3*X**2+Q4*X**3+...)

The big advantage to rational polynomials is that they are MUCH more flexible

(e.g. they can take on an infinite value, something that a normal polynomial

can't do for any finite value of X).

POLY can tie "knots" too. That is, fixed points and slopes. (Sorry, no

slopes for rational polynomials). This means that you can have POLY make the

polynomial fit exactly at a few points, or have a specified slope at some

point, or a zero second derivitive at another point, and fit as best as it can

everywhere else.

POLY can also determine the group of functions that best fit your data from a

set of 60 common functions like:

1, X, X**2, X**3, ..., 1/X, 1/X**2,..., EXP(X), X*EXP(X), ...,

EXP(-X), X*EXP(-X), ..., SIN(X), COS(X), SIN(2*X), COS(2*X),...

POLY will automatically select the ones from this list that when taken as a

group will best fit your function. This is no trivial task! and sometines

doesn't work.

To run POLY just enter "POLY" (without the quotes). It's all interactive.

The first thing it will ask is if you want to read the data from a file. If

you want to try this, respond "Y" (without the quotes) and give it the file

name "POLY.DAT" when asked for the file name. POLY can read data in

free-format from any two of up to 20 columns of data in a file. Otherwise you

can enter the data from the keyboard.

You can edit the data. That is, list it and change values. Then when you

have verified it, POLY will ask you if you want automatic selection of

functions. You can try this and see what you get. It really should be sort

of self-explanatory.

You can see the form of the curve-fit by responding "Y" (without the quotes)

when asked. What POLY will list is the actual FORTRAN code, just like you

would put into a program to use the curve-fit. It may look a little strange,

but that's because the polynomial is in Horner's form. It will work!

You can check to see how the curve-fit does by responding "Y" (without the

quotes) when asked to check agreement. You can evaluate the curve-fit at as

many locations as you want (just enter a blank line or "NO" to quit

evaluating). You can perform several curve-fits on the same data without

entering it again. Just wait until the end and it will asy you "another fit

on the same data?(Y/N)."

Dudley J. Benton

TVA Engineering Lab

P.O. Drawer E

Norris, TN 37828

(615) 632-1887

.sp 1

.in 10

.de

Gentle User,

POLY is a program that allows you to fit a curve to a set of data points.

POLY can fit normal polynomials like:

Y=C1+C2*X+C3*X**2+C4*X**3+...

or rational polynomials like:

Y=(P1+P2*X+P3*X**2+P4*X**3+...)/(Q1+Q2*X+Q3*X**2+Q4*X**3+...)

The big advantage to rational polynomials is that they are MUCH more flexible

(e.g. they can take on an infinite value, something that a normal polynomial

can't do for any finite value of X).

POLY can tie "knots" too. That is, fixed points and slopes. (Sorry, no

slopes for rational polynomials). This means that you can have POLY make the

polynomial fit exactly at a few points, or have a specified slope at some

point, or a zero second derivitive at another point, and fit as best as it can

everywhere else.

POLY can also determine the group of functions that best fit your data from a

set of 60 common functions like:

1, X, X**2, X**3, ..., 1/X, 1/X**2,..., EXP(X), X*EXP(X), ...,

EXP(-X), X*EXP(-X), ..., SIN(X), COS(X), SIN(2*X), COS(2*X),...

POLY will automatically select the ones from this list that when taken as a

group will best fit your function. This is no trivial task! and sometines

doesn't work.

To run POLY just enter "POLY" (without the quotes). It's all interactive.

The first thing it will ask is if you want to read the data from a file. If

you want to try this, respond "Y" (without the quotes) and give it the file

name "POLY.DAT" when asked for the file name. POLY can read data in

free-format from any two of up to 20 columns of data in a file. Otherwise you

can enter the data from the keyboard.

You can edit the data. That is, list it and change values. Then when you

have verified it, POLY will ask you if you want automatic selection of

functions. You can try this and see what you get. It really should be sort

of self-explanatory.

You can see the form of the curve-fit by responding "Y" (without the quotes)

when asked. What POLY will list is the actual FORTRAN code, just like you

would put into a program to use the curve-fit. It may look a little strange,

but that's because the polynomial is in Horner's form. It will work!

You can check to see how the curve-fit does by responding "Y" (without the

quotes) when asked to check agreement. You can evaluate the curve-fit at as

many locations as you want (just enter a blank line or "NO" to quit

evaluating). You can perform several curve-fits on the same data without

entering it again. Just wait until the end and it will asy you "another fit

on the same data?(Y/N)."

Dudley J. Benton

TVA Engineering Lab

P.O. Drawer E

Norris, TN 37828

(615) 632-1887

December 18, 2017
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