Matrix node output browser

The matrix browser displays cross-tabulated data and enables you to perform operations on the matrix, including selecting cells, copying the matrix to the Clipboard in whole or in part, generating new nodes based on the matrix selection, and saving and printing the matrix. The matrix browser may also be used to display output from certain models, such as Naive Bayes models from Oracle.

The File and Edit menus provide the usual options for printing, saving, exporting output, and for selecting and copying data. See the topic Viewing output for more information.

Chi-square. For a cross-tabulation of two categorical fields, the global Pearson chi-square is also displayed below the table. This test indicates the probability that the two fields are unrelated, based on the difference between observed counts and the counts you would expect if no relationship exists. For example, if there were no relationship between customer satisfaction and store location, you would expect similar satisfaction rates across all stores. But if customers at certain stores consistently report higher rates than others, you might suspect it wasn't a coincidence. The greater the difference, the smaller the probability that it was the result of chance sampling error alone.

• The chi-square test indicates the probability that the two fields are unrelated, in which case any differences between observed and expected frequencies are the result of chance alone. If this probability is very small—typically less than 5%—then the relationship between the two fields is said to be significant.
• If there is only one column or one row (a one-way chi-square test), the degrees of freedom is the number of cells minus one. For a two-way chi-square, the degrees of freedom is the number of rows minus one times the number of columns minus one.
• Use caution when interpreting the chi-square statistic if any of the expected cell frequencies are less than five.
• The chi-square test is available only for a cross-tabulation of two fields. (When All flags or All numerics is selected on the Settings tab, this test is not displayed.)

Generate menu. The Generate menu contains node generation operations. These operations are available only for cross-tabulated matrices, and you must have at least one cell selected in the matrix.

• Select Node. Generates a Select node that selects the records that match any selected cell in the matrix.
• Derive Node (Flag). Generates a Derive node to create a new flag field. The flag field contains T for records that match any selected cell in the matrix and F for the remaining records.
• Derive Node (Set). Generates a Derive node to create a new nominal field. The nominal field contains one category for each contiguous set of selected cells in the matrix.