Getting Started with a Simple example
This is a brief introduction to the three main stages in analysing data with the
Windows version of GenStat. These are: loading data, performing the required
analysis, and saving the results. If you are already familiar with the GenStat
command language you may like to refer to Using the GenStat Command Language.
A more complete introduction to GenStat can be found in the online Guide to GenStat:
Introduction (pdf). This can be found by selecting the Introduction
item on the GenStat Guides section of the Help menu.
Loading Data
The easiest way to enter new data into GenStat is by using a spreadsheet.
From the menu bar select Spread, New, then
Create. This will open a dialog in which you can specify the size and type of
the spreadsheet. For the time being, the default settings can be used; press the
OK button to continue. A window containing a spreadsheet of the default size
(100 rows and 10 columns) will appear, with a * in every cell. This is how
GenStat represents a "missing value", that is an unknown quantity. To enter
data in the spreadsheet click on the cell in row 1, column C1. This will be
highlighted in blue, indicating that it is the current cell. You can now type
a value, and press Enter to move on to the next cell (row 2, column C1). Enter
the following set of data in columns C1 and C2:
After entering the value 12 you will need to click on row 1, column C2 to move
to the second column. Once all the data has been entered select the Spread menu
again, this time locating the Delete option from which you can
select Empty Rows + Columns. This will shrink the spreadsheet to
the size of the data that you have entered. The spreadsheet should now appear as shown above.
The data you have entered is displayed in the spreadsheet window but cannot be
accessed by GenStat until it is saved as GenStat data. By default, this should
happen automatically when you switch focus to any other window; you should see
a number of messages appearing in the Output window to indicate this has
occurred. If you select click on the Data tab on the
left hand panel, and then double-click the All Data,
you should obtain a listing of the variables C1 and C2 (see below). If, for any reason, this automatic
update does not appear to work (for example, it may have been disabled on the
Spreadsheet Options) you can make the update manually. From the Spread
menu select Update, then Changed Data to GenStat.
This will create GenStat data structures
containing your data. Messages should now appear in the Output Window showing
that your data has been successfully loaded.
You can also use the Toolbar to save your data to GenStat, by clicking on the
button.
Statistical Analysis
The Stats item on the menu bar lists various forms of analysis that can be
performed on your data. For example, you can fit a straight line to the data
that you have just entered. Select Linear Models from the
choices listed under Regression Analysis on the Stats
menu. This will bring up the Linear Regression menu that allows you to specify your data and various other options
controlling the analysis. Click in the box labelled Response Variate and then
double-click on C2 in the Available Data list. Likewise, set the Explanatory
Variate to C1. Then click on Run. The following image shows the
menu with the data entered.
The results from the regression of C2 on C1
will appear in the Output window. You can use the scroll bar to move up and
down in the window if it is not large enough to display all the output at
once. Returning to the Linear Regression menu you can use the Further Output
button to produce more output from the analysis. Select Graph of Fitted Model
and then press OK. This will open the GenStat Graphics Viewer containing a graph of the
data and fitted line.
Saving the Results
The results of the regression analysis are contained in the Output Window. You
can save this to a file by selecting Save As from the
File menu and then
specifying an appropriate name for the saved output. Note that the File menu
always operates on the currently active window, which is indicated by
highlighting the title bar. Click on the title bar of the Output Window to
ensure it is the active window before using the File menu.
See Also
