4. Sub Function Descriptions: localTransformPoints

• localTransformPoints

  • Description:

  This function tranforms between Local Coordinates and Geographical Coordinates. Local refers to the rotated coordinate system where X is positive offshore and y is oriented alongshore. The function can go from Local to World and in reverse. Note: Regardless of transformation direction, local Angle and localOrigin should stay the same. Input can be vectors or matrices. Note, for rotation to equidistant grids, localTransformEquiGrid should be used. Note, this only performs horizontal rotations/ transformations. More informations on coordinate systems is in Section 5.

  • Input:

  Variable	Size	Description
  localAngle	[1x1]	The localAngle should be the relative angle between the new (local) X axis and old (Geo) X axis, positive counter- clockwise from the old (Geo) X. Units are degrees.
  localOrigin	[1x2]	Location of Local (0,0) in Geo Coordinates. Typically first entry is E and second is N coordinate.
  Xin	Variable	Local (X) or Geo (E) coord depending on transformation direction. Units should be same as localOrigin.
  Yin	Variable	Local (Y) or Geo (N) coord depending on transformation direction. Units should be same as localOrigin.
  directionFlag	[1x1]	directionFlag = 1 or zero to indicate whether you are going from Geo ->Local (1) OR Local--> Geo (0)

  • Output:

  Variable	Size	Description
  Xout	Variable	Local (X) or Geo (E) coord depending on transformation direction
  Yout	Variable	Local (Y) or Geo (N) coord depending on transformation direction

  • Required Core Sub-Functions:

    None.