Command manual

Command list

COORDINATE_SYSTEM_FUNCTION

Coordinate system
*COORDINATE_SYSTEM_FUNCTION
"Optional title"
csysid, $x_0$, $y_0$, $z_0$
$\hat{x}_x$, $\hat{x}_y$, $\hat{x}_z$, $\bar{y}_x$, $\bar{y}_y$, $\bar{y}_z$

Parameter definition

VariableDescription
csysid Unique identification number
$x_0$, $y_0$, $z_0$ Coordinate of origin
options: constant, fcn
$\hat{x}_x$, $\hat{x}_y$, $\hat{x}_z$ Direction of local x-axis
options: constant, fcn
$\bar{y}_x$, $\bar{y}_y$, $\bar{y}_z$ Vector needed for the definition of the local y- and z-axis
options: constant, fcn

Description

This command defines a local cartesian coordinate system. The parameters can either be constants or functions.

The origin is located at ($x_0$, $y_0$, $z_0$) and the local x-direction is ($\hat{x}_x$, $\hat{x}_y$, $\hat{x}_z$). The local z-direction is defined as $\hat{\mathbf{z}} = \hat{\mathbf{x}} \times \bar{\mathbf{y}} / \vert \hat{\mathbf{x}} \times \bar{\mathbf{y}} \vert$ and the local y-direction as $\hat{\mathbf{y}} = \hat{\mathbf{z}} \times \hat{\mathbf{x}}$.

Example

Coordinate system defined with functions

A local coordinate system with its origin following sensor ID=8 and with prescribed, time dependent, direction cosines

*COORDINATE_SYSTEM_FUNCTION
"test"
1, fcn(10), fcn(11), fcn(12)
fcn(13), fcn(14), 0, fcn(15), fcn(13), 0
*FUNCTION
10
xs(8)
*FUNCTION
11
ys(8)
*FUNCTION
12
zs(8)
*FUNCTION
13
cos(360*t)
*FUNCTION
14
sin(360*t)
*FUNCTION
15
-sin(360*t)