function

LieGroups.SO3.Euler.inNonsingularChart

True when Euler coordinates stay away from their sequence singularity

Public declarations

Explicit source declarations; dimensions, modifications and defaults are shown as written, without evaluation.

Role	Name	Type	Dimensions / attributes / default	Description
input	`angles`	`Real`	`[3]`
input	`sequence`	`LieGroups.SO3.Euler.Axis`	`[3]`
input	`margin`	`Real`	`(min=0.0) = 1.0e-6`	Lower bound on the relevant sine or cosine magnitude
output	`valid`	`Boolean`

Modelica declarations and implementation

Show parameters, interfaces and source

Parameters, inputs, outputs, defaults and equations from the source file.

function inNonsingularChart
  "True when Euler coordinates stay away from their sequence singularity"
  input Real angles[3];
  input LieGroups.SO3.Euler.Axis sequence[3];
  input Real margin(min=0.0) = 1.0e-6
    "Lower bound on the relevant sine or cosine magnitude";
  output Boolean valid;
protected
  Boolean properEuler;
  Real singularityMeasure;
algorithm
  assert(LieGroups.SO3.Euler.validSequence(sequence),
    "Euler sequence cannot repeat adjacent axes");
  properEuler := sequence[1] == sequence[3];
  singularityMeasure := if properEuler
    then abs(sin(angles[2]))
    else abs(cos(angles[2]));
  valid := margin < 1.0 and singularityMeasure > margin;
end inNonsingularChart;