.Modelica.Mechanics.MultiBody.Frames.TransformationMatrices.from_nxy

Information

Syntax

T = TransformationMatrices.from_nxy(n_x, n_y);

Description

It is assumed that the two input vectors n_x and n_y are resolved in frame 1 and are directed along the x and y axis of frame 2 (i.e., n_x and n_y are orthogonal to each other). The function returns the orientation object T to rotate from frame 1 to frame 2.

The function is robust in the sense that it returns always an orientation object T, even if n_y is not orthogonal to n_x. This is performed in the following way:
If n_x and n_y are not orthogonal to each other, first a unit vector e_y is determined that is orthogonal to n_x and is lying in the plane spanned by n_x and n_y. If n_x and n_y are parallel or nearly parallel to each other, a vector e_y is selected arbitrarily such that e_x and e_y are orthogonal to each other.

See also

Frames.from_nxy.

Interface

function from_nxy
  extends Modelica.Icons.Function;
  import Modelica.Math.Vectors.length;
  import Modelica.Math.Vectors.normalize;
  input Real n_x[3](each final unit = "1") "Vector in direction of x-axis of frame 2, resolved in frame 1";
  input Real n_y[3](each final unit = "1") "Vector in direction of y-axis of frame 2, resolved in frame 1";
  output TransformationMatrices.Orientation T "Orientation object to rotate frame 1 into frame 2";
end from_nxy;