Creation functions

Do I need teaching material about creating functions, what can be used for creation and how to use it?

I have already searched the sites of LibreOffice and OpenOffice, and found minimal material.

Anyone have any tips where to find it (site/book)?

Criação de funções

Necessito de material didático sobre a criação de funções, o que pode ser usado para criação e como usar?

Já procurei nos sites do LibreOffice e OpenOffice, e encontrei mínimo material.

Alguém tem alguma dica onde encontrar(site/livro)?

A function is simply a block of code which can accept information, do some processing and then return some information. This is programming. Functions are not necessarily specific to Calc. So in order to create functions, it is best to know how to program in Basic and use the UNO API.

There is a great deal of information spread around on these subjects. However, for the best single document, OpenOffice Macros Explained (OOME) by Andrew Pitonyak is available (click here) in PDF. It has a complete section on Calc as well as a great deal of other information.