Data processing system with user definable mathematical functions and a method for using same

摘要

A user definable mathematical function is implemented on a data processing system including a data terminal. The user definable mathematical function includes a user definable mathematical formula having at least one operand which is as yet unspecified or undetermined, but which will be retrieved from a source or location specified in the mathematical function. Execution of the user defined mathematical function is initiated by a data terminal selector device associated with the user definable mathematical function. Upon execution of the user defined mathematical function, a variable value is retrieved from the specified source and substituted for the unspecified operand in the user defined mathematical formula. The user defined mathematical formula is executed and a result of the execution provided. A method for providing and using such a user definable mathematical function is also provided.