Generally Matlab/Octave scripts work on processing section of data which are generated from some kind of experiment or other events e.g. image processing. It is not possible for a user to enter value of each pixel manually in a processing algorithm. It is needed to read the image file directly and import data into variable in workspace.
In mathematics, Function is a relation from a set of inputs to a set of possible outputs where each input is related to exactly one output. This concept is borrowed by programming languages to simplify the code by avoiding unnecessary repetition.
Octave showing the perfect compatibility with MATLAB keeps its tag of being called open source clone of MATLAB. This article is a continuation of the series dealing with variables and constants in Octave.