12. A method for creating a graphical program, comprising: displaying a function block in a graphical program, wherein the function block is configured to perform a first function, wherein the function block comprises one or more inputs and one or more outputs, and wherein the graphical program comprises a plurality of interconnected blocks which visually indicate the functionality of the graphical program; receiving user input selecting the function block to configure the function block; receiving user input assembling a second graphical program that visually specifies calculation of attributes of the one or more outputs based on attributes of the one or more inputs, wherein the second graphical program comprises a second plurality of interconnected blocks which visually indicate the calculation of the attributes of the one or more outputs, wherein said receiving user input assembling is performed in response to the user input selecting the function block; executing the graphical program; and during said executing the graphical program, the function block automatically determining the attributes of the one or more outputs of the function block based on the attributes of the one or more inputs to the function block, wherein said determining comprises executing the second graphical program.
12. A method for creating a graphical program, comprising: displaying a function block in a graphical program, wherein the function block is configured to perform a first function, wherein the function block comprises one or more inputs and one or more outputs, and wherein the graphical program comprises a plurality of interconnected blocks which visually indicate the functionality of the graphical program; receiving user input selecting the function block to configure the function block; receiving user input assembling a second graphical program that visually specifies calculation of attributes of the one or more outputs based on attributes of the one or more inputs, wherein the second graphical program comprises a second plurality of interconnected blocks which visually indicate the calculation of the attributes of the one or more outputs, wherein said receiving user input assembling is performed in response to the user input selecting the function block; executing the graphical program; and during said executing the graphical program, the function block automatically determining the attributes of the one or more outputs of the function block based on the attributes of the one or more inputs to the function block, wherein said determining comprises executing the second graphical program. 14. The method of claim 12 , further comprising: connecting the function block to receive the one or more inputs from a second block comprised in the graphical program; and connecting the one or more outputs of the function block to a third block comprised in the graphical program.