Category : Science and Education
Archive   : FIT2_11.ZIP
Filename : FIT2.DOC

FIT2.EXE, curve fitting and data modeling
*****************************************

__________________
³ ³
³ version 1.11 ³
³ ³
³ June/1990 ³
³__________________³



What is FIT2 ?
**************

FIT2 is a tool that allows you to find closed-form solution to both
linear and non-linear modelling problems.



What are the main resources of FIT2 ?
*************************************

- FIT2 produces screen graphics that are automatic scaled and
displayed in CGA mode (or EGA, VGA, depending the graphic card
you desire). A HERCULES GRAPHICS ADAPTER with CGA emulator will
also work fine.

- FIT2 provides very powerful data analysis tools that include not
only linear regression analysisbut non-linear and specially
polynomial regression.

- FIT2 allows you to extrapolate values for any curve.

- with FIT2 you can make data transformation like adding something
to Y series, or generating a random Y series, etc.

- FIT2 uses a ASCII open format for data files and it provides a
simple way to export and import data from/to popular spreadsheet
and others packages interfaced with FIT2.


Why FIT2 ?
**********

I wrote FIT2 because I use data analysis daily and needed a little
more than the spreadsheets had to offer. I do have several other
curve fitting programs at my disposal, and no doubt they have some
great features, but I have yet to find one with this friendly
interface.
I was tempted to write a full curve fitting in the beginning, but
I have decided against it since comercial packages actually does
quite nicely under most circumstances: they come with expensive
packages, they have high level routines, and they will do most
everything you need a curve fitting program will do. Because of
that, I decided to simply write something simple to solve the common
problems that I have.


Are there any outstanding bugs that you know of?
************************************************

FIT2 has been tested on an IBM PC, PC/XT, PC/AT, PC386 and laptops as
TOSHIBA T1000, T1200 computers. No troubles were detected. You can
use up to 5000 data points. Sometimes overflow occurs because in this
version I have used single precision values.


Lets explain each of the features of FIT2:
******************************************

1.) data entry - keyboard

This is the mechanism used to introduce data using the
keyboard, without edition. After FIT2 is loaded the default
is the keyboard data entry option. You can move to other
options pressing up or down the arrow key.

2.) data entry - file

This feature allows you to select a file (extension .DAT) to
load the data to the memory and work. Pressing the up or down
arrow key, point to the name of the file desired to load and
press RETURN.
The seventy first characters of the 10 top lines are displayed
with the reference position of each digit of the file data.
Choose the correct distribution of digits and enter with the
loading data.

example:

seventy characters of the 10 top lines: xxxxxx (below)

1 5 81 41
2 3 82 42
3 4 85 43
4 4 82 42
5 8 83 41
6 11 87 42
7 52 88 43
8 12 89 40
9.5 7 111 19
12 11 101 58

1........01........01.......01........01.....................
³ ³ ³ ³
³ ³ ³ ³final position
³ ³ ³ ³of Y variable
³ ³ ³
³ ³ ³
³ ³ ³initial position
³ ³ ³of Y variable
³ ³
³ ³final position
³ ³of X variable
³
³
³initial position
³of X variable

Enter the values for each position or ENTER for defaults.
For exit without loading file enter 0 (zero) for each
question.


3.) Save current data

This feature allows you to save the current data in disk
files with .DAT extension name.
Only after saved the current data, the TITLE will be
displayed on the top of each graphic screen.
The format used for saving data on disk is with five
integers and four decimals, separeted by a dot (#####.####).

4.) Edit current data

This is how you change the values of the current memory. The
options are showed at the bottom line and it is possible to:

- delete a value pressing DEL and giving the order of the
value to be deleted.

- modify a value pressing F1 and giving the order and
contents of X and Y variables.

- insert a new value pressing INS and giving the position
as well the contents of X and Y values.

- move to bottom (END) or top (HOME) or each page up (PGUP)
or each page down (PGDN).


5.) Print current data

This option allows you to output the current value on the
printer.


6.) Linear regression

This option shows graphically the points introduced and the
best line fitted to these points, with the equation and the
coefficient of determination.


7.) Exponential regression

This option shows graphically the points introduced and the
best exponential curve fitted to these points, with the
equation and the coefficient of determination.


8.) Geometric regression

This option shows graphically the points introduced and the
best geometric curve fitted to these points, with the
equation and the coefficient of determination.


9.) Logarithmic regression

This option shows graphically the points introduced and the
best logarithmic curve fitted to these points, with the
equation and the coefficient of determination.


10.) Polynomial regression

This option shows graphically the points introduced and the
best polynomial curve fitted to these points, with the
equation and the coefficient of determination, initialy for
the second degree equation. The program allows you to try
other degrees up to 9 and extrapolate values too.


11.) XY operations

This option allows you to manipulate data for normalizing,
adding, etc ... , giving chances to prepare the data for
fitting.

The options of XY operations are:

-swap X with Y

change the values of X with Y


-new Y = log(Y)

calculate Y as log(Y)


-new Y = power of Y
p
calculate Y as Y , while p is the power


-new Y = exp(Y)

calculate Y as exp(Y)


-new Y = 1/Y

calculate Y as the inverse of Y (or 1/Y)


-add something to Y

add a constant value to Y


-multiply Y by something

multiply Y by a constant value


-X ordination, swaping Y

put the X series in crescent order, changing the position
of Y also


-X ordination, Y independent

put the X series in crescent order, without moving Y


-Y Random generation, same X

generating a new Y series with randomic numbers, using the
same old X


-new Random file generation

generate a new file with Y series as a random series and X
series with the crescent order of series


-replace Y values

substitute all the Y values that satisfy one of the three
following conditions:

G for greater than a determined value
E for equal than a determined value
S for smaller than a determined value

replace the checked values by a new value in all Y series

example: substitute all values greater than .3 by .1
entries: g .3 .1


-return to main menu

go back to main menu


12.) Line graphics

This option shows graphically the points introduced connected
by lines, in the current order.


13.) setup MENU

This option allows you to choose:


graphic video card:

Choose between CGA, EGA and VGA graphic card. Make sure
that the data are saved before go to this option, because
any error may delete all data in memory.


grid option:

Choose between grid ON or grid OFF, for all graphics.


hard copy quality:

Choose between low and high quality for printer outputs.


When you change a setup option, a file called FIT2.CFG is
saved with the new data. If in the begining of job no file
called FIT2.CFG is found, the standard FIT2.CFG file is
created. The contents of this file is the following:

description: options:
internal video option 1(CGA) 2(EGA) 3(VGA)
microsoft video option 2(CGA) 9(EGA) 12(VGA)
back color option 1(CGA) 2(EGA) 2(VGA)
internal grid option 1(on) 2(off)
color grid option 1(on) 2(off)
internal qual prin opt 1(draft)2(high)
printer quality option 1(draft)2(high)


14.) Program references

Some information about the program and rules for shareware
conditions.

Files that come with FIT2
*************************

FIT2.EXE - executable file

FIT2.DOC - document file and manual

FIT2.CFG - standard configuration file

EXAMPLE1.DAT - example number 1

EXAMPLE2.DAT - example number 2


Learning with an example:
*************************

Type FIT2 and press RETURN

Press the down arroy key till the DATA ENTRY - FILE and press RETURN

Press RETURN and the file EXAMPLE1.DAT will be loaded

Press RETURN again because the file is a default type

Wait for the loading

Choose the LINE GRAPHIC option and press RETURN

Choose the LINEAR REGRESSION option and press RETURN

Choose the POLYNOMIAL REGRESSION and press RETURN

Press the N key in POLYNOMIAL REGRESSION and choose a degree 4

etc...........................................................



You can copy FIT2
*****************

FIT2 - June/1990
Welcome to FIT2
This is used supported software, or SHAREWARE.
You are encourage to make copies for your friends,
as well as trying out the program for yourself.
If you like it and continue to use it regularly,
please register your use by sending US$ 15.00 to:
ARMANDO CAVANHA, account number 113000609:01800285338,
10411 WESTHEIMER - BOX 42370 - Texas Commerce Bank
Lakeside - HOUSTON, TX, 77242-2370, USA
To receive the newest version of FIT2,
send a copy of the US$ 15.00 receipt to:
ARMANDO OSCAR CAVANHA FILHO
RUA RIBEIRO GUIMARAES 80/903
RIO DE JANEIRO - BRAZIL - 20511



Please make copies of the module FITZ.EXE only.


Thank you,


ARMANDO CAVANHA