To begin Statsgraphics Plus, click on the Windows Start button in the lower left hand corner of the computer. The Program directory contains the Statsgraphic Plus folder where you should click on the SWGIN icon.

The program will contain two windows, which are the comments window and the data file window. Begin by putting needed information into the comments window and the data into the data file window. The data file window contains rows and columns similar to Excel, however you can not label you columns and rows in Statsgraphics because it will interfere with the calculations.

Here is an example of the data file.

The data file contains total phosphorus concentrations in the first row. The second row is the month the measurement was taken un numerical form. The following ten rows are the Fourier Series terms needed to complete the analysis. This coincides with the first column being the dependent variable and the following columns being the independent variables.

Here is an example of the information contained in the comments window.

The data file was set up in Excel. Using manual entry for both the concentrations and the month the sample was taken. The Fourier Series colums were set up in the first row and the formulas were copied and pasted to the end of the data file.

The Fourier Series terms are as follows:

Sin (k*pi*m/12) + Cos (k*pi*m/12)

To begin the multiple regression analysis, click on the tool button that looks like this . This will bring up the regression analysis window.

Highlight Col_1, click in the dependent variable square, and finally, click the arrow button. Do the same thing for the independent variables. Click ok.

The results will show up in this window.

The default is the regular multiple regression. In order to do a step-wise multiple regression, use your right mouse button and click on the multiple regression results window. You will get this window.

Change the Fit to either forward or backward selection and click OK. The results will show up in the multiple regression results window. You may want to print your results between each run because the program does not save the results from run.

To save your project, goto the file window and click on Save the Portfolio. This will prompt you to name the project file and to name the data file. When opening the project again, be sure to open both the project file and the data file.

Project files are saved as *.sgp

Data files are saved as *.sf.