# Point: about

## Points

Points can be created:

- manually (entering coordinates)
- by propagation from existing points, with the aid of a transformation
- within the propagation or extrusion from other entities

## Point coordinates

A point could be defined by its coordinates in a coordinate system for definition (see Coordinate system: about ).

## Point defined by propagation

A point could be defined by propagation from another point with the aid of a transformation.

## Parameter setting

The point coordinates can be defined using algebraic expression. The algebraic expression can contain:

- constants
- geometric parameters (created beforehand)
- basic mathematical functions using operators : +, -, *, /, ( )
- usual mathematical functions admitted by FORTRAN

The mathematical functions are described in section Functions.