Curve Fit Contents
Curve Fit Table of Contents

Topics:

Application Synopsis

Compute X Page

Compute Y Page

Curve Page

Data Page

List View

Plot View

Registration Form

Resolution Page


Application Synopsis
Curve Fit Synopsis

The Curve Fit application allows you fit data pairs to a curve you select.  The supported curve types are polynomial, log-log polynomial, and semi-log in both X and Y.  You are allowed to select a curve order of from 1 through 10 for the polynomial curve types.  The fit method used is least squares.  To help determine how good the fit is for the curve selected, the sum of the absolute differences and the coefficient of fit performance are reported.  The best fits usually have the smallest sum of absolute differences and a coefficient of performance near 1.000.  The curve is automatically refitted anytime a change in data or curve type occurs.  Two views of the data are supported which are a listing (List View) and a plot (Plot View) view.

Starting a New Data Set

To fit a curve to a new data set, select New Data when asked to select a data file in the opening dialog.  You immediately get a tabbed dialog that has the following three pages.

o	The Curve Page allows you to define a data set title, title the X & Y axes, select a curve type, and set the curve order.

o	The Data Page allows you to enter, import, edit, delete, and rearrange data pairs.

o	The Resolution Page allows you to set the data precision and display-entry format.

You can also start a new data set by selecting the New Fit Button on the tool bar.  Enter a data title and the axes titles; pick the curve type and order; select the data resolution and display format; and enter or import the data pairs.  Click OK when you are satisfied with the data set.

Saving a Data Set

Once you have entered a data set, select the Save… or Save As… option of File menu or the Save Button (floppy disk graphic) on the tool bar to save the data.  Enter a file name appropriate for your data, and click the OK button.  This application automatically recognizes data files having a dat extension.

Loading an Existing Data Set

To load a previously saved data set, use the opening file dialog to find the file on your system.  When you have found the file, double click it or click it and then click the Open Existing button to load it.  The application reads the file and displays pertinent information in the List View.  You may reload a previously saved data set at any time by selecting the Open Button (opening folder graphic) on the tool bar or by selecting Open from the File menu.

Printing

You may print the data set by selecting the Print Button (printer graphic) on the tool bar or by selecting the Print option from the File menu.  The hard copy will have the same format as the List View.

Importing Data

You may import data from a text file by selecting the Import button on the Data page.  The X-Y data pairs may be delimited with a space, comma, semicolon, double quote, and single quote or any combination of these characters.  If the file contains more than two columns of data, only the first two are used and the remaining columns are ignored.  If you have data in an Excel file, you can export it to a text file and then import it into this application.

Limitations

Until the application is licensed, you are limited to only 7 data points.

The application is easy to use.  It has been tested with a data set in excess of 30,000 pairs and although a little slow with a data set that large it ran just fine.  Select a previously saved file you wish to read from any drive/directory on your system and your off and running.

Data precision is limited to 14 decimal places maximum and 0 decimal places minimum.


Compute X

This page is only active when you have elected to fit your data to the X = Ae^BY semi-log curve.  You may enter a Y value in the edit control and X will be computed using the fitted curve coefficients when you click the Compute X button.


Compute Y

This page is active when you have elected to fit your data to the Y = Ae^BX semi-log curve or any polynomial.  You may enter an X value in the edit control and Y will be computed using the fitted curve coefficients when you click the Compute Y button.


Registration Form

Your Name: _____________________________________________

Note:	Type/print your name and company below EXACTLY as it appears in the Registration

dialog in the Help Menu of the Application.

Registration Dialog Name: _____________________________________________

Registration Dialog Company:__________________________________________

Please type or print clearly the following information:

Address: __________________________________________________________

City: _________________________________      State: _____      Zip: __________

E-Mail Address: _______________________________

Check the programs you wish to Register.

Curve Fit:	_____  $20.00

Find String:	_____  $15.00

HTML Merge:	_____  $20.00

Search/Replace String:	_____  $15.00

Set Text File Line Break:	_____  $10.00

Touch File Date/Time:	_____  $10.00

Both Search/Replace & Find String:	_____  $25.00

Both Search/Replace & HTML Merge:	_____  $30.00

I have enclosed a

___ Check	___Money Order	(Check One)

Preferred Registration Code delivery:

___ Mail	___ E-mail	(Check One)

Please include a self addressed envelope for mail delivery to speed up the response.

__________________________________________________________________________

Please make checks payable to Richard Floersch.

Mail this form and your check or money order to:

Richard Floersch

7307 W 89th Terr

Overland Park, Ks	66212

__________________________________________________________________________


Selecting Curve Types
Curve Page

The Curve page allows you to enter a title that describes your data, assign labels to the X & Y axes, and select a curve type.  You may select a polynomial, log-log polynomial, or one of two semi-log curves.  For the polynomial curves you may set the fit order of the curve from a 1st (straight line) to a 10th order curve.  You must enter at least one more data pair than the order of the curve you select (e.g., for a 3rd order curve you must enter at least 4 data pairs).  You may change the curve type or order at any time and the application will refit the data to the new choice.


Entering
Data Page

The Data page allows you to add, import, modify, delete, and rearrange data pairs.  Enter the data pairs in the controls you titled on the Curve page and click the Add button to add a new data pair to the data set.  Double clicking on a data pair loads their values in your titled controls where either may be modified.  Click the Edit button to replace the highlighted pair, click the Insert button to insert the data above the highlighted pair, or click the Add button to add the new pair to the data set.  To delete one or more pairs, highlight the data pairs in the data list you want to eliminate then click the Delete button.  You may rearrange the data pairs by highlighting a pair and clicking the move Up or Down buttons to exchange the pair with the pair above or below it respectively.  To import data pairs from a text file, click the Import button.  The data file may contain multiple columns of data but only the first two columns are used.  The data pairs must be separated by a comma, a semicolon, a space, a tab, a single quote, or a double quote in any combination.  The first column will be interpreted as the X value.  Importing will stop when the end-of-file is reached, an error occurs, or seven data pairs have been read if the application is not licensed.


Setting
Resolution Page

The Resolution page allows you to specify the data entry/display format and number of precision digits you want your data to have.  The two formats supported are standard (e.g., 13400.) or exponential (e.g., 1.34e+04).  Each data point can be 16 digits, a sign, and a decimal point.  The data precision is set to five by default and is restricted to from 0 (no decimal point) to 14 decimal positions.  If you want fewer or more digits to the right of the decimal, enter the number you want in the appropriate decimal places control.


Listing

List View

The List View is a scroll window that allows you to view or print your data set and the pertinent information about the fitted curve.  The List View is the primary display window.  If you pop up the Plot Viewand kill the List View window, select New List Window option from the Window menu to redisplay it.


Plot

Plot View

You can get a plot of the data pairs and the fitted curve by selecting the New Plot Window option from the Window menu or by clicking the Plot Button (graph) on the tool bar.  Click the Zoom Button to double the size of the plot.  Click the Zoom Button again to restore the plot to its original size.  Each data pair is represented by a red asterisk.  The green line is a plot generated by evaluating the fitted equation.