Reflectance values express the percentage of light that is reflected back from a surface, the difference having been absorbed or transmitted by the surface. Reflectances of room surfaces are used in determining coefficient of utilization values for luminaires.
The last three lines show you how to define your own awk function. The format is simple -- type function, then the function name, and then the parameters separated by commas, inside parentheses. After this, a { } code block contains the code that you'd like this function to execute.
In computer programming, an anonymous function is a function definition that is not bound to an identifier. Anonymous functions are often: arguments being passed to higher-order functions, or used for constructing the result of a higher-order function that needs to return a function. If the function is only used once, or a limited number of times, an anonymous function may be syntactically lighter than using a named function. Anonymous functions are ubiquitous in functional programming languages and other languages with first-class functions, where they fulfill the same role for the function type as literals do for other data types.