I.2.2.1 “initWith3Points” method

“initWith3Points” method is used to define a coordinate system with the coordinates of three points A, B and C. (See the definition of “CORD2C”, “CORD2R” and “CORD2S” in [Sof04b].) This function has 5 arguments:

• A string argument corresponding to the type of coordinate system being build. Three values are accepted: “CORDC”, “CORDR” and “CORDS”. (Remark that the “2” of Nastran has disappeared.)
• A DataBase object that will allow the definition of coordinate system wrt the base coordinate system.
• An integer argument corresponding to the reference coordinate system (coordinate system wrt which the coordinates of points A, B and C are given). A coordinate system corresponding to this integer must be defined in the DataBase passed as previous argument.
• A vector containing the coordinates of point A. (Point A corresponds to the origin of the coordinate system.)
• A vector containing the coordinates of point B. (Point B defines the axis Z of the coordinate system. More precisely, point B is on axis Z.)
• A vector containing the coordinates of point C. (Point C defines the axis X of the coordinate system. More precisely, the axis X of the coordinate system is defined in the half-plane defined by the straight-line AB and the point C.)

The three vectors mentioned above are actually Arrays of three real values corresponding to the coordinates of points given in coordinate system identified by the integer argument.

Note that no check is made in a DataBase to ensure that the data are consistent. (For example, checking that the reference coordinate system exists.)