Introduction Fitting program - goal is to vary the fit parameters to minimize the chi-square defined as: data points errors function Fit parameters f{g,x) = 2πsqrt(length/g)

Basketball Movie Go to the notes for Week 3 find data Excel file time Y-velY-pos

Import to IGOR Make waves - called: tt, ypos and yvel Make table - Under Windows - new table Then cut from the Excel file and paste into IGOR table

Graph Position Data

Fit Data to a Polynomial This dialog box - from choosing Curve Fitting under Analysis in the main menu Built - in functions are available 3 terms or quadratic Specify waves for the fit

Results of Fit

Fit in a Range of Data With a graph selected - under the Graph menu select Show Info - then move cursors over the data points that define the range to be fitted

Procedure 1.Define error wave and inverse error wave. In this example: err and errinv= 1/err. 2.In the graph of period vs length, use markers for data and show error bars. 3.Define the user-function in the Procedure window. In this example pend 4.Make fitting coefficients wave and set to reasonable starting values. In this example coef.

Evaluating Fit

Terminal Velocity