N-Nearest-Neighbour interpolation

Table of Contents

• Description
• Options
• YAML example

Description

This method supports source fields that are defined on points at the grid corners, cells, or edges.

For each target point, this method searches for the "n" nearest source points. Using the weighting method selected by the user, the interpolation stencil will be generated from the found source points.

Grid connection information is not taken into account by this interpolation method.

Source field

Options

• Number of source points per target point (mandatory)
• Weighting method (default: weighted: arithmetic_average)

  • arithmetic_average

    Simple average

    Target field

    n = 1	n = 4	n = 9

    
    

  • distance_weighted

    Inverse distance weighting

    Target field

    n = 1	n = 4	n = 9

    
    

  • gauss_weighted

    Gaussian filter

    This method has an additional optional scaling parameter.
    Through empirical tests a good default value has be determined. (default: gauss_scale: YAC_INTERP_NNN_GAUSS_SCALE_DEFAULT)

    Target field

    n = 1	n = 4	n = 9

    
    

  • zero

    Zero weight

    Sets the weight to zero (number of source points per target has to be 1).
    This method can be useful if a weight file generated by YAC is supposed to be used by another software that does not support the Fixed value interpolation. In this case this option can be used to set target points to "0.0".

YAML example

interpolation:
  - nnn:
      n: 4
      weighted: arithmetic_average