Stattucino Statistical Analysis

The data applet offers the possibility of the statistical analysis of data. Start the applet by clicking the blue button above, a spreadsheet will appear on screen. The results of a statistical analysis are given in tables and graphs. The tables can be exported in html to a browser window by choosing file in the applets results window and the clicking "export to browser".

• Working with data
  There are a few sample datasets for you to work with. Users who wish to analyse their own data can upload a file or type the data in the spreadsheet window. If you choose to upload a file, the data should be a plain text file (with extension .txt) with the data values separeted by spaces or tabs. Currently the number of data points is limited to 100; there is no limit on the number of variables. The data are processed by our server and passed on to the applet. There are no copies of your data stored on our server. Click here to upload a file
• Analyse data
  The applet provides a number of graphs and regression procedures. There are also a few procedures for transforming data. The data window contains a spreadsheet and a menubar from which you select the appropriate statistical analysis. For instance if a logistic regression is selected from the menu, a dialog box is shown. Using the dialog box select a dichotomous response variable and one or more explanatory variables. Interactions are added to the model by selecting two or more variables in the left panel, and clicking the button add interaction". Model terms are removed from the analysis by clicking the remove button. Click "done" to start the analysis.

  File menu

  Data files   Opens a text file with example data, the contents of this file are displayed in the datasheet.

  Clear Clears the contents of the spreadsheet

  Quit Closes this program

  Edit menu

  Copy   Copies a value from the spreadsheet.

  Cut   Removes a value from the spreadsheet

  Paste   Pastes a value in the cell in the spreadsheet

  Data menu

  Calculate   Creates new variables by calculating sums, products, quotients, and differences of two variables.

  Transform   Calculates a transformation, such as the logarithm, or square root of the variables. Invalid values are replaced by missing values. The following Mathematical functions are available.

  • ln. Returns the natural logarithm of a nonnegative number.

  • exp. Returns the value of e raised to a power. For example, exp(1) returns 2.71828.

  • sin. Returns the sine of an angle.

  • square root. Returns the square root of a nonnegative number.

  • abs. Returns the absolute value of a number.

  • cos. Returns the cosine of an angle.

  • tan. Returns the tangent of an angle.

  • log10. Returns the logarithm to the base 10.

  Datatype   Changes the datatype of a variable. The default datatype for a variable is numeric. Use the menu to change the datatype to factor. Parameters for factor variables are calculated using the cornerpoint parameterisation. This means that for a factor with n levels the first level is set to zero. Using this parameterisation, the value of the first level is included with the constant term. The estimates for the levels 2,¼,n describe the deviation from the first level. In words, the first level has the role of a baseline measurement.

  Delete   Deletes a variable or observation. This operation cannot be undone.

• Obtaining your results.
  The results from a statistical analysis are shown in the results window. To export them to your browser, select "Export to Browser" from the file menu in the results window. A new Browser window opens containing a html document with the tables from your statistical analysis. From the browser you can save or print the document. Click here to obtain a sample html output