WebStat is a statistical computing environment for the World Wide Web. It is written in the form of a Java applet. WebStat should run on any of the three major platforms (Mac, PC, Unix). It only has the minimal requirement of a Java-capable Web browser which almost everyone on the Web now has. If you do not have such a browser, the following links are to Web browsers which are Java-capable.
If you obtain one of the above browsers, WebStat will automatically load onto your computer when you press the button at the top of this page.
We, the creators of WebStat, think you will find it easy to use, and we hope you enjoy working with our package!
Who created it and why?
WebStat was created and programmed by Webster West with help from Todd Ogden. Both of whom are in the Department of Statistics at the University of South Carolina.
The package was created as an initial attempt to solve many of the problems which exist with the delivery and use of modern statistical software. Many times statisticians develop procedures in languages such as Splus, SAS, Minitab, etc.., which are very specific to statisticians. Students and other potential users may not have access to these languages, and therefore may not be able to use the procedures. By using Java and the World Wide Web, WebStat should reach the broadest possible audience of any statistical software of its kind.
How do I get data into WebStat?
Here is where things get interesting. WebStat has a number of ways for users to input data. You may enter data the old fashioned way by typing numbers in by hand. WebStat is equipped with a functional data table for this purpose. To navigate through the data table, you may use the arrow keys, the vertical and horizontal scrollbars, the tab key and the mouse. Unfortunately, due to the current Java implementations in some browsers, all of these navigation options may not be available to you. For example, when using Netscape Navigator Gold 3.0 on a Sun workstation, the arrow keys do not work properly. The backspace and delete keys may be used to edit highlighted cells. At this point, only numbers can be typed into the individual cells. WebStat does, however, allow for scientific notation, so the "e" key is functional.
If your data is already in a file in a World Wide Web accessible location, you may import the data into WebStat by providing the URL of the file. Note: If you are working with WebStat from a site other than its primary location, you may have difficulty loading data in this way if the URL is not on the site on which you are working. This is due to access restrictions placed on applets. If this feature doesn't work, try using the primary location.
To load data via a URL, simply go to the Data menu and
select "Get data." From the sub-menu, select "from URL." A
dialog window will then pop up which prompts you to enter the URL.
Type the URL (something like http://...), and then press the okay
button. The data will then be loaded into WebStat. As an
example, try typing the URL,
http://www.stat.sc.edu/~west/webstat/data/iris.dat into the dialog window as shown below.
If you are embedding WebStat in your own HTML document, you can specify a data set to be loaded when the user clicks the download button by adding a parameter statement like the one below within the applet tag.
<PARAM name=dataurl value="data/iris.dat">
Due to limitations on applets, most browsers will not allow you to interact with your local file system. Therefore, you can't read and write local files. The only browser which will allow you to do this is Hotjava. For this reason some menu items contain the phrase "Hotjava Only" in parentheses. This is to emphasize the fact that these options are only available for this browser.
In order to work around the problems with local file access, you may paste data contained in a local file into WebStat. To do this, go the Data menu and select "Paste data." A dialog window will then pop up which contains a text field. Using your mouse, select your data and then paste it into the text field. You may also type your data into the text field if you so choose. When you are finished, click the okay button. You data is then submitted to WebStat. The picture below shows Fisher's iris data in the dialog window.
As a final option, you may also work with sample data sets. At present, the following data sets are available:
More data sets will be available soon. To use one of these data sets simply go to the Data menu and select "Sample datasets." From the sub-menu,select the desired dataset. The picture below shows Fisher's iris data loaded into WebStat.
Once you have loaded your data into WebStat you may change a variable name by clicking on the name in the column of interest. A dialog window will then prompt you to enter the new variable name.
How do I format data for WebStat?
You can specially format a data set, by adding a header to the file you import into WebStat. The header for the file containing Fisher's iris data is given below:
varnames = sepall sepalw petall petalw
This header lets WebStat know that the dataset contains four variables, and it provides the names for each variable.
If all the variables in your dataset don't contain the same number of observations, you can let WebStat know this by adding another line to the header beginning with the string "nobs =." To see how this works, try pasting the following snippet into WebStat.
varnames = old new nobs = 4 6 1 2 3 4 5 6 7 8 9 10
The nobs statement above tells WebStat there are two variables and that the first variable has four observations and the second variable contains 6 observations.
What can WebStat do with data?
WebStat is currently equipped to do almost everything you need for an introductory statistics course. It contains basic graphical and numerical statistical procedures. The numerical procedures are under the Stat menu, and the graphical procedures are under the Graphics menu.
In terms of numerical procedures, WebStat offers:
When you select one of these procedures under the Stat menu, a dialog window will pop up and ask you for the necessary information to perform the procedure. After entering the information, click on the okay button. The results from the selected procedure based on the information you provided will then be sent to the Statistics Window.
On the graphics side of things, WebStat offers:
When you select one of these procedures under the Graphics menu, a dialog window will pop up and ask you for the necessary information to perform the procedure. If you select more than one variable, the procedure will be applied to each variable selected and the results will be plotted on the same scale. The results from the selected procedure based on the information you provided will then be sent to the Graphics Window (except for stem and leaf plots which are sent to the Statistics Window).
Note that if you have problems with either numerical or graphical procedures it may be due to your Web browser being out of date. You may want to download a newer version.
How do I customize graphics?
When you create a graphic in WebStat you may want to customize it by adding a title and/or a bounding box. You can do this by placing the mouse over the graphic of interest and then double clicking. Within some browsers, this does not work effectively all the time. If you have problems, please let us know. A dialog window like the one below should pop up on your screen which gives the option of changing the title or adding/removing the bounding box. When you click the okay button, the changes are made to the graphic.
You may also customize graphics by displaying several graphics within the Graphics Window at the same time. The Graphics Window may be divided into a grid of graphics. To do this, go to the Graphics Window and select Multiple Plots under the Graphic menu. A dialog window will then prompt you to enter the number of rows and the number of columns of graphics you would like displayed in the Graphics Window. For example, if you wanted a two by two grid of plots you would enter "2x2" into the text field as shown below.
Please note that if you decide to do multiple plots then all graphics currently being displayed are lost.
After clicking on okay above, one construct a grid of plots as shown below.
A new an exciting feature for WebStat 1.0 is the ability to do color graphics. You may change the background and drawing color for graphics by choosing the Color Scheme option under the Graphic menu. A dialog window as shown below will then display the background and drawing color options.
Note that if you are doing multiple plots in WebStat, then the color scheme applies to the current plot and all plots that follow. An example of a color plot in WebStat 1.0 is shown below. Warning: Colors in WebStat 1.0 don't seem to work with some versions of Netscape on Macs!
Due to the restrictions placed on applets by most browsers, saving statistical results in WebStat is not as easy as it should be. In the future, a move to a trusted applet framework should make things easier. For now, you may save results in the Statistics Window by shading the desired results with your mouse and then pasting them into a file. This isn't too much of a hassle, and it may be the way most textual results are typically saved. To save graphics one must resort to the idea of screen dumps. For example on a Unix X-windows system,one can type the command xwd -out name.gif at the prompt and then click on an open window to dump a picture of the window into a GIF file. There are similar options on Macs and PCs. If you have the Hotjava browser, you may save the results in the Graphics Window directly to a GIF file by choosing the "Save Graphic" option under the Graphic menu.
How do I exit from WebStat?
In order to exit from WebStat, go to the WebStat menu and select exit. This will close all three windows which were opened when WebStat loaded onto your machine. Most browsers keep a copy of WebStat in cache memory so that if you choose to fire up WebStat again after closing it, it will not have to be loaded over the World Wide Web a second time.
How do I include the WebStat applet in my HTMl page?
If you would like to include WebStat 1.0 in your HTML document, simply paste the information below into it.
<CENTER> <APPLET codebase="http://www.stat.sc.edu/~west/webstat/version1.0/" code="webstat1.class" width=400 height=50> </APPLET> </CENTER>
How do I download WebStat to run on my Web server?
Some people have expressed an interest in downloading WebStat to their local server for faster access. We have established a site for downloading WebStat 1.0. Simply go there and follow instructions. Webstat can only be downloaded as an applet at this time. In the future, a stand alone application will also be available.
Where do I go with questions or comments about WebStat?
If you have any questions, comments or bug reports, please email firstname.lastname@example.org. You might want to check out the bug list for the 1.0 version to see if your bug has already been reported.