Help:

• The x-y pairs should be input one pair per line with the x value (the independent variable) first. The x and y values can be separated by spaces, a tab, or a comma. You can copy and paste from Excel.
• Examples of the uses of the fit functions.
• You need to input rough guesses for the fit parameters. Sometimes just guessing "1" for each parameter will work.
• For fitting functions with a "c" parameter, you can choose to fix the value. This option allows you to use "c" as a parameter without varying the value during least squares adjustment.
• If the calculation doesn't converge,
  1. Try using convergence damping.
  2. In cases of slow convergence, enter the results from the previous non-converged run as guesses for the next run.
  3. Use the "Fit values from initial guesses" output to refine your guesses. In other words, vary your input guesses to decrease the initial residuals.
• Leave the guess for any unused parameter blank.
• For fitting a user input function see John Pezzullo's Nonlinear Least Squares Curve Fitter.
• If the plotting screen doesn't finish running, you need to use a more recent version of the Java plugin for your browser.
• The Java plotting routines are courtesy of Leigh Brookshaw.