You can visit Engineered Software's home page on the web at http://www.kagi.com/authors/johng/ for the latest product releases.
Once you register DataFit, you can obtain priority email support by sending email to johng@kagi.com.
You can turn off the tip of the day by de-selecting "Show Tips on Startup" below.
You can use the toolbar at the top of the window for accessing common operations.
You can paste tab delimited data from other applications, such as Microsoft Excel, directly into the Spreadsheet.
You can make a custom group of models to solve from the "Available Solutions" list by clicking the "Create Solve Group" button.
Regression models in the "Available Solutions" list are in order from best to worst fit.
DataFit can perform regression on data containing up to 9 independent variables.
THE 'coolest' way to travel is by motorcycle.
DataFit provides a Function Template for easily inserting built in functions for user defined models. When defining a user model, place the curser in the place you want to insert the function, click on the Functions button, then select the function you want to insert.
By holding the mouse over the toolbar buttons for a second will show the tool tips describing the button's operation.
You can solve regression models built in to DataFit with either a Linear (Least Squares) or Non-Linear (Levenberg-Marquardt) solver. This option is selected in the Solution Setup window.
DataFit supports many mathematical functions to use when defining your own regression models. For a comprehensive list, see the help topic "User Defined Regression Models" in the online help.
You do not have to perform regression analysis in order to create plots. Plots can be created from the spreadsheet data only.
It takes a lot of typing to create tip of the day files.
You can save notes along with your project files by typing them in the text box at the bottom left corner of the DataFit window.
Many of the features in DataFit are a result of comments and suggestions from registered users.
You can choose to not include the standard deviation column in the spreadsheet if you do not know your measurement errors. This produces an "unweighted" fit.
You can choose to include the standard deviation column in the spreadsheet if you know your measurement errors. This produces a fit weighted by uncertainty.
You can copy the results of a regression analysis into tab delimited format by clicking the "Copy" button in the Results window.
A list of the most recently used files appears at the bottom of the "File" and the "Plot" menus for quick access.
You can move the legend and footnotes on a plot by clicking and dragging them to a new location.
You can contribute to the feature list of future versions of DataFit by sending your comments to johng@kagi.com.
DataFit got its start in 1988 as a personal project to fit equations to Nonlinear induction curves and Watts per Pound curves for transformer core steels.
You can use the Enter key and the arrow keys to navigate the spreadsheet.
You can select multiple cells in the spreadsheet by holding down the "Ctrl" key while clicking cells.
You can select multiple rows and columns in the spreadsheet by clicking the mouse in the first desired cell, then pressing the "Shift" key and clicking in the last desired cell.
You can insert rows into the spreadsheet by using "Insert" under the "Edit" menu.
You can delete rows from the spreadsheet by using "Delete" under the "Edit" menu.
Spreadsheet data can be sorted with up to 3 sort keys by choosing "Sort" under the "Edit" menu.
You can use the "Fill" command under the "Edit" menu to enter functions, linear sweeps, functions of other columns or constants into the spreadsheet.
You can remove solved regression models from the "Available Solutions" list by clicking the "Clear Fits..." button.
You can use the "Exchange" command under the "Edit" menu to exchange two columns of data in the spreadsheet.
You can scale ranges of spreadsheet data with the "Scale" command under the "Edit" menu.
You can translate ranges of spreadsheet data with the "Translate" command under the "Edit" menu.
You can import delimited files saved from other applications, such as Microsoft Excel, directly into DataFit by choosing "Import" from the "File" menu.
You can export the spreadsheet data to delimited ASCII files to be read by other applications by choosing "Export" from the "File" menu.
You can specify the layout when printing the spreadsheet data using "Page Setup" under the "File" menu.
You can change the spreadsheet cell formatting under the "Format" menu.
You can define your own regression model by selecting "Define User Model" under the "Solve" menu.
You can obtain statistical information about your input data by choosing "Data Statistics" under the "Solve" menu.
You can bypass the Solution Setup window for repetitive solutions by unchecking "Prompt for Solution Setup" under the "Solve" menu.
If a solution fails, you can find out why by choosing "View Log" from the "Solve" menu.
Solution preferences, such as nonlinear residual and iteration limits, can be changed by choosing "Preferences..." under the "Solve" menu.
After data modification, you can re-solve the last group of solved models by choosing "Last Solved Models" in the Solution Setup window.
You can export documented BASIC or C Source code from fitted models to include in programs you have written. Select the desired model and choose "BASIC" or "C" under the "Export" menu.
DataFit's online help contains a step by step tutorial. You can access it by choosing "DataFit Tutorial" under the "Help" menu.
You can plot more than one regression model at a time by multi-selecting them in the Available Solutions list and choosing "New" under the "Plot" menu.
You can multi-select regression models that are non-adjacent in the "Available Solutions" list for creating a plot by holding down the "Ctrl" key while clicking on the desired models in the list.
You can multi-select a range of adjacent regression models in the "Available Solutions" list by clicking the first desired model, then hold the "Shift" key and clicking the last desired model.
You can import data or equations from saved plots or solutions into the current plot window by choosing "Import" under the "Plot" menu.
You can copy plots to the windows clipboard as metafiles or bitmaps by using "Copy to Clipboard" under the "Plot" menu.
You can display 2 dimensional discreet data as a continuous line by checking "Display Line" in the "Data" tab of the 2D Graph Properties window.
You can show ticks on both X and Y axis on two dimensional plots by checking "Ticks on Both Axis" in the "Axis" tab of the 2D Graph Properties window.
You can reset axis settings to default values by clicking the "Default" button in the "Axis" tab of the 2D Graph Properties Window.
You can hide or display Major and Minor Gridlines with options in the "Axis" tab of the Graph Properties window.
You can hide or display the plot legend by checking or unchecking the "Display Legend" checkbox in the "Data" tab of the Graph Properties window.
You can modify the legend text displayed on a plot by modifying it in the "Data" tab of the Graph Properties window.
You can change the granularity of the 3D surface mesh in the "Data" tab of the 3D Graph Properties window.
Footnote text can be Center, Left or Right justified with options in the "Footnote" tab of the Graph Properties window.
You can add additional footnote text to plots with options in the "Footnote" tab of the Graph Properties window.
3D plots can be rotated dynamically in the "3D appearance" tab of the Graph Properties window by dragging the scrollbars.
You can save data independent plot settings as defaults by arranging the plot to your liking and clicking "Save Current Settings as Default" in the Graph Properties window.
You can add axis titles to your plot in the "Titles" tab of the Graph Properties window.
You can change marker styles, colors and sizes in the "Data" tab of the Graph Properties window.
You can change the background color of a plot in the "Appearance" tab of the Graph Properties window.
You can perform many mathematical operations on data in the DataFit Data Calculator.
You can define and plot functions in the Data Calculator by clicking the "Eq" button.
You can create a Normal, or Gaussian, probability distribution in the Data Calculator (Dist button).
User defined models can contain up to 20 coefficients, or parameters. The coefficients can be entered in any order.
You can, but aren't required to, specify derivatives for user defined models by clicking "Dy/Dv" in the User Defined Models window.
You can specify initial estimate Rules for user defined models by clicking "Rules" in the User Defined Models window.
You can specify your own initial estimates for regression models with graphical assistance when solving single regression models.
You can use the "Range" feature when specifying initial estimates for user defined models to check for the presence of "local minimums" in the nonlinear solution.
No matter where you go, there you are.
You can evaluate a regression model as well as parameter derivatives at any value of the independent variable in the "Evaluate" tab of the Results window.
Minor upgrades are typically free to registered users of DataFit. You can download the latest code from our home page at http://www.kagi.com/authors/johng/.
You can connect to Engineered Software on the Web directly from DataFit. Choose "Engineered Software on the Web" from the "Help" menu.
