Abstract: A method of creating a user-defined function in a spreadsheet application is provided. The user-defined function is callable by a calling label in the spreadsheet application. A formula is received in the spreadsheet application. The formula is transferred to a function sheet of the spreadsheet application to define at least a portion of a function body. An interface is defined by identifying the calling label, an input parameter and a result parameter of the user-defined function. The function body operates on an argument corresponding to the input parameter and generates a result corresponding to the result parameter. The interface is stored in association with the function body to create the user-defined function.

Abstract: The invention includes a method for testing a spreadsheet cell. Du-associations are collected for the spreadsheet cell. The cell's execution trace is tracked. After the user validates the cell, the du-associations that participated in the execution trace are marked as executed. Du-associations for other cells that are affected by the testing a spreadsheet cell are similarly marking as exercised. If the user changes a cell's contents, the collected du-associations for the cell are discarded and the steps of collecting test elements, tracking execution traces, and marking are repeated. Cells that depend on the changed cell also repeat these steps. After the user marks a cell as validated, a validation symbol is shown on the cell. If the cell's validation status is later brought into question, the validation symbol can change or be removed entirely. The invention also includes a method for providing a user with feedback of the testedness of the spreadsheet cells.

Abstract: The invention includes two methods for testing a spreadsheet region. Du-associations are collected for the spreadsheet region. In the Straightforward approach, du-associations are collected for each cell in the region. Each cell's execution trace is tracked. After the user validates a cell, the du-associations for the cell that participated in the execution trace are marked as executed. In the Region Representative approach, a region representative represents the region. Each cell's execution trace is tracked. After the user validates a cell, the du-associations for the region representative that participated in the execution trace for the validated cell are marked as executed. Du-associations for other cells that are affected by the testing of a spreadsheet region are similarly marked as covered. If the user changes a shared non-constant formula, the collected du-associations for the region are discarded and the steps of collecting test elements and tracking execution traces are repeated.

Abstract: User-defined function capabilities in a spreadsheet application allow users to create new named functions that are defined using the spreadsheet formula paradigm. A user may define spreadsheet functions from formulae entered in a worksheet or function sheet of a spreadsheet application. The formula interface is well known to spreadsheet users; therefore, expanding the formula feature to provide encapsulated functions that can be imported, exported, customized, and compiled supplies new power and flexibility to users who do not wish to learn a programming language. Furthermore, the user-defined functions in spreadsheets represent vectors and matrices as “first class” values, similar to Boolean values, numbers, and strings.