<< Overview of CelestLab CelestLab Flight dynamics >>

CelestLab >> About > CelestLab > Conventions used in CelestLab

Conventions used in CelestLab

Conventions used in CelestLab

Naming conventions

All CelestLab exported names begin with the prefix "CL_" (for functions) or "%CL_" (for predefined data).

Most function names have an additional prefix (2 or 3 letters) that indicates the purpose of the function:

Vectors

In CelestLab most functions are vectorized. Arguments of functions are generally vectors of size :

Frame transformation matrices

The frame transformation matrix P(i->f) is defined as the matrix transforming vector coordinates relative to an initial frame Ri to coordinates relative to a final frame Rf :

The rotation matrix that transforms the basis vectors of Ri into the basis vectors of Rf is then P(i->f)' (P transpose).

For example, the transformation matrix for a rotation of angle θ around the X axis is :

Quaternions

CelestLab contains operators for the management of quaternions :

NB: Quaternions as defined in CelestLab are consistent with rotation matrices.

Hypermatrices

Scilab's hypermatrix type (mlist 'hm') is partly overloaded in CelestLab. Hypermatrices should be of dimension 3.

A hypermatrix is considered as an array of matrices: A = [A1; A2...; An], where Ak = A(:,:,k).

The overloaded operations are :

<< Overview of CelestLab CelestLab Flight dynamics >>