QUADRATIC REGRESSION APPLET
Scroll beyond the applet to see instructions and explanations
This applet has two functions: plotting and finding the quadratic
function (of the form ) which best approximates the user supplied data. Use it as follows:
- Put the data to plot and analyze in the Data section. Though the variables
default to x (the independent variable) and y (the dependent variable), they
can be renamed. Renaming them will cause the graph to be updated. The values
are entered one per line. The data can be integers as well as real numbers. Scientific notation is allowed (for ex. 2.1E3 for 2100 or 2.1E-3 for 0.0021). You can also copy and paste data from any other application using the keys CTRL C to copy and CTRL V to paste.
- The buttons work as follows: CLEAR will clear the data, the plot
area and the RESULTS area. PLOT will plot the data as points. ANALYZE
will find the quadratic function which best approximates the data, plot it
and display its equation in the RESULTS area.
- The plot area (top, right) will show the plot.
- The RESULTS area is used to communicate with the user.
- Error messages will be displayed
there, for example if the number of values is not the same for both variables.
- Information will also be displayed there. For example, when the user clicks
on ANALYZE, the equation of the regression function will appear there,
as well as the error associated with this function and the correlation coefficient. The error is obtained with the formula where y denotes the y-values of the data points to fit and denotes the computed y-values.
- The number of digits after the decimal point can be changed. Simply clicked on the button between "RESULTS" and "precision".
This applet was developed by Dr. Philippe
B. Laval, at Kennesaw State
This work was funded in part by:
The National Science Foundation # DUE-9952568
The US Department of Education FIPSE #P116B00178