coords.Coords.to_coordsys#

Coords.to_coordsys(cs)#

Express the coordinates in another coordinate system.

Parameters#

csCoordSys: Target Cartesian coordinate system in which to express the current coordinates.

Returns#

Coords: New Coords object representing the same points, but with coordinates expressed in coordinate system cs.

See Also#

from_coordsys(): perform the inverse transformation

Examples#

>>> X = Coords([[0.0, 0.0, 0.0],[1.0, 0.0, 0.0]])
>>> print(X)
[[0.  0.  0.]
 [1.  0.  0.]]
>>> from hellotriangle.coordsys import CoordSys
>>> CS = CoordSys(oab=[[0.5, 0.5, 0.0], [1.0, 0.5, 0.0], [0.5, 1.0, 0.0]])
>>> print(CS)
CoordSys: trl=[0.5 0.5 0. ]; rot=[[1. 0. 0.]
                                  [0. 1. 0.]
                                  [0. 0. 1.]]
>>> print(X.to_coordsys(CS))
[[-0.5 -0.5  0. ]
 [ 0.5 -0.5  0. ]]

Let’s now create a new coordinate system that is translated and rotated with respect to the original coordinate system:

>>> CS = CoordSys(oab=[[0.5,0.,0.],[1.,0.5,0.],[0.,1.,0.]])
>>> print(CS)
CoordSys: trl=[0.5 0.  0. ]; rot=[[ 0.7071   0.7071  0.      ]
                                  [-0.7071   0.7071  0.      ]
                                  [ 0.      -0.      1.      ]]
>>> print(X.to_coordsys(CS))
[[-0.3536  0.3536  0.      ]
 [ 0.3536 -0.3536  0.      ]]
>>> print(X.to_coordsys(CS).from_coordsys(CS))
[[ 0.  0.  0.]
 [ 1. -0.  0.]]