Orthogonality (computer science)
In computer science , orthogonality is a design principle, namely the free combinability of independent concepts.
For example, in Algol 60 , the following was already valid : where any expression of a type may appear, any expression of this type may appear (for example, any complex arithmetic expression for calculating an index to designate a field element). Later in Fortran 66 , however, only an expression of the type “constant 1 times variable plus constant 2 ” could be used as an (integer) index , whereby two of the three values (including the associated arithmetic symbols) could be missing. This was a violation of the (much earlier formulated) design principle of orthogonality.
Orthogonality also means that several programs do not have the same functions. For example, under Linux the sophisticated selection of files is only made by the find program . On the other hand, find can only select files and has no additional functions; however, it can be combined with all other commands. The tar program can combine several files into one archive; it is combined with gzip to compress it . gzip can only compress one file and cannot select or combine files.
In microprocessors , orthogonality is a certain property of the instruction set , see there.
For magnetic storage media, orthogonality is a recording technique, see Perpendicular Recording .