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Epsilon doc

Open zeffii opened this issue 3 years ago • 0 comments

Epsilon for arithmetic precision needs a canonical document, it is used in several nodes. Some notes here regarding user configurable epsilons. This is a chance to use a consistent explanation for this precision/tolerance parameter.

Epsilon is hard coded in these nodes:

  • nearest point on mesh
  • raycaster lite
  • object_nodes\points_from_uv_to_mesh
  • spatial\random_points_on_mesh
  • ...more

Epsilon n is described as some formulation of 1 / 10 ** self.epsilon:

  • edges intersect mk3 (range is 3 significant digits to 5..)
  • merge mesh 2d lite , this parameter is called "accuracy" (range from 3 to 12)
  • modifier_make\fractal_curve
    • here self.precision is the controllable parameter. epsilon = 10 ** (- self.precision)
    • min=0, max=10, default=7
    • helpful description "decimal precision of coordinates for calculations"
  • spatial\delaunay_2d_cdt
    • default=5, min=3, max=12,
    • description: For nearness tests; should not be zero
  • surface\adaptive_tessellate ,called accuracy
    • default=5, min=3, max=12,
    • description='Some errors of the node can be fixed by changing this value'
  • surface\tessellate_trim: called accuracy
    • epsilon = 1.0 / 10**self.accuracy
    • default=5, min=3, max=12,
    • description='Some errors of the node can be fixed by changing this value'

other property names or descriptions using Epsilon:

  • curve\rbfCurve , epsilon (range 0.0 to 1.0)
    • affecting shape of a produced Curve
  • field\mesh_surface_field , epsilon (range 0.0 to 1.0)
    • Epsilon parameter of used RBF function; it affects the shape of generated field. The default value is 1.0
  • field\minimal_sfield and field\minimal_vfield
    • it affects the shape of generated field. The default value is 1.0.
  • generators_extended\triangle called "Tolerance"
    • for remove doubles (no max, no min default 1e-6)
  • logic\neuro_elman.py
    • coefficient participates in the learning assessment function
  • surface\interpolating_surface and surface\min_surface_from_curve
    • default = 1.0, min = 0.0,
    • epsilon is a socket, The docs do not cover it.
    • scipy.interpolate.Rbf
      • Epsilon: Adjustable constant for gaussian or multiquadrics functions - defaults to approximate average distance between nodes
  • surface\minimal_surface
    • default = 1.0, min = 0.0,
    • docs: Epsilon parameter of used RBF function; it affects the shape of generated surface. The default value is 1.0.
    • ( still is the same as scipy.interpolate.Rbf )

zeffii avatar Aug 08 '21 16:08 zeffii