# Paths: about

## Definition

A path is a line support, on which the user can evaluate a spatial quantity.

## Use

A path is used to plot 2D spatial curves.

## Geometric shapes

The path can be as follows:

- rectilinear (straight segment)
- curvilinear (arc of circle, helicoïdal line)

## Mesh

The mesh of a path is based on a user-defined discretization: computation points are regularly spaced on the line of the support.

## Types of path

Types of path are as follows:

Type of path | Shape of path | Definition |
---|---|---|

path defined by two points |
straight segment / arc of circle helicoïdal line |
two points * (graphical or numerical capture) |

arc defined by three points | arc of circle |
three points * (graphical or numerical capture) |

arc defined by center, radius and angles | arc of circle |
center coordinates, radius, starting angle and ending angle |

parametrized path |
straight segment / arc of circle helicoïdal line |
parameter functions |

## Parameter setting

The user can use geometric parameters to define the path by the numerical mode.