What is a matrix spreadsheet?

A STATISTICA Matrix Spreadsheet (*.smx) is a spreadsheet file with a strictly defined format that can be used as input in several modules of STATISTICA (e.g., Cluster Analysis, Multidimensional Scaling, SEPATH). Matrix spreadsheets must meet the following conditions:

  • The number of cases (rows) = the number of variables (columns) + 4.

  • The matrix must be a square matrix, and the case names should be the same as the variable names.

  • The last four cases contain the following case names and information:

Means: The mean of each variable is given in this row; this case can be left empty (i.e., do not enter anything in this row) for Similarities and Dissimilarities matrices.

Std.Dev.: The standard deviation of each variable is given in this row; this case can be left empty (i.e., do not enter anything in this row) for Similarities and Dissimilarities matrices.

No.Cases: This required entry is the number of cases from which the matrix was produced, not the number of cases (rows of data) in this matrix file.

Matrix: This required entry represents the type of matrix file; 1 = Correlation, 2 = Similarities, 3 = Dissimilarities, and 4 = Covariance.

When entering these last four cases into the matrix file manually, be sure to spell the case names exactly as they appear above (i.e., Means, Std.Dev., No.Cases, and Matrix).

While a matrix spreadsheet looks identical to a regular spreadsheet, analyses that require matrix input (such as Multidimensional Scaling) only consider input spreadsheets that are also matrix spreadsheets.

You can create a matrix spreadsheet from any analysis that provides the means to create a matrix of results (e.g., Basic Statistics - Correlations, Multiple Regression, Cluster Analysis, Multidimensional Scaling, and Structural Equation Modeling (SEPATH)). To create the matrix, click the button. Note that clicking this button does not cause STATISTICA to save the matrix file to disk, rather it causes STATISTICA to create the special matrix spreadsheet. This matrix spreadsheet is always displayed in an individual window (regardless of the settings in the Options dialog box - Output Manager tab or in the Analysis/Graph Output Manager dialog box). You can; however, add the spreadsheet to a workbook or report using the or buttons, respectively.

When you save a matrix spreadsheet (using Save or Save As from the File menu), STATISTICA detects that it is in this special matrix form, and sets the default file extension to *.smx.