SAGA 9.9.1 | Tool Library Documentation

Cubic Spline Approximation


Description

This tool approximates irregular scalar 2D data in specified points using C1-continuous bivariate cubic spline. Minimal Number of Points: minimal number of points locally involved in spline calculation (normally = 3) Maximal Number of Points:npmax: maximal number of points locally involved in spline calculation (required > 10, recommended 20 < npmax < 60) Tolerance: relative tolerance multiple in fitting spline coefficients: the higher this value, the higher degree of the locally fitted spline (recommended 80 < k < 200) Points per square: average number of points per square (increase if the point distribution is strongly non-uniform to get larger cells) Author: Pavel Sakov, CSIRO Marine Research Purpose: 2D data approximation with bivariate C1 cubic spline. A set of library functions + standalone utility.


References


Parameters

 NameTypeIdentifierDescriptionConstraints
InputPointsshapes, inputSHAPES--
Target Systemgrid, input, optionalTARGET_TEMPLATEuse this grid's system for output grids-
OutputTarget Gridgrid, outputTARGET_OUT_GRID--
OptionsAttributetable fieldFIELD--
Target Grid SystemchoiceTARGET_DEFINITION-Available Choices: [0] user defined [1] grid or grid system Default: 0
Cellsizefloating point numberTARGET_USER_SIZE-Minimum: 0.000000 Default: 1.000000
Westfloating point numberTARGET_USER_XMIN-Default: 0.000000
Eastfloating point numberTARGET_USER_XMAX-Default: 100.000000
Southfloating point numberTARGET_USER_YMIN-Default: 0.000000
Northfloating point numberTARGET_USER_YMAX-Default: 100.000000
Columnsinteger numberTARGET_USER_COLSNumber of cells in East-West direction.Minimum: 1 Default: 101
Rowsinteger numberTARGET_USER_ROWSNumber of cells in North-South direction.Minimum: 1 Default: 101
RoundingbooleanTARGET_USER_FLATRound bounding coordinates to multiples of cell size. Ignored if cell size has decimal places.Default: 1
FitchoiceTARGET_USER_FITS-Available Choices: [0] nodes [1] cells Default: 0
Grid Systemgrid systemTARGET_SYSTEM--
Minimal Number of Pointsinteger numberNPMIN-Minimum: 0 Default: 3
Maximal Number of Pointsinteger numberNPMAX-Minimum: 11 Maximum: 59 Default: 20
Points per Squarefloating point numberNPPC-Minimum: 1.000000 Default: 5.000000
Toleranceinteger numberKSpline sensitivity, reduce to get smoother results, recommended: 80 < Tolerance < 200Minimum: 0 Default: 140

Command Line


Usage: saga_cmd grid_spline 6 [-SHAPES ] [-FIELD ] [-TARGET_DEFINITION ] [-TARGET_USER_SIZE ] [-TARGET_USER_XMIN ] [-TARGET_USER_XMAX ] [-TARGET_USER_YMIN ] [-TARGET_USER_YMAX ] [-TARGET_USER_COLS ] [-TARGET_USER_ROWS ] [-TARGET_USER_FLAT ] [-TARGET_USER_FITS ] [-TARGET_TEMPLATE ] [-TARGET_OUT_GRID ] [-NPMIN ] [-NPMAX ] [-NPPC ] [-K ]
  -SHAPES:                Points
	shapes, input
  -FIELD:                 Attribute
	table field
  -TARGET_DEFINITION:
                               Target Grid System
                               	choice
                               	Available Choices:
                               	[0] user defined
                               	[1] grid or grid system
                               	Default: 0
  -TARGET_USER_SIZE:   Cellsize
	floating point number
	Minimum: 0.000000
	Default: 1.000000
  -TARGET_USER_XMIN:   West
	floating point number
	Default: 0.000000
  -TARGET_USER_XMAX:   East
	floating point number
	Default: 100.000000
  -TARGET_USER_YMIN:   South
	floating point number
	Default: 0.000000
  -TARGET_USER_YMAX:   North
	floating point number
	Default: 100.000000
  -TARGET_USER_COLS:      Columns
	integer number
	Minimum: 1
	Default: 101
  -TARGET_USER_ROWS:      Rows
	integer number
	Minimum: 1
	Default: 101
  -TARGET_USER_FLAT:      Rounding
	boolean
	Default: 1
  -TARGET_USER_FITS:      Fit
	choice
	Available Choices:
	[0] nodes
	[1] cells
	Default: 0
  -TARGET_TEMPLATE:       Target System
	grid, input, optional
  -TARGET_OUT_GRID:       Target Grid
	grid, output
  -NPMIN:                 Minimal Number of Points
	integer number
	Minimum: 0
	Default: 3
  -NPMAX:                 Maximal Number of Points
	integer number
	Minimum: 11
	Maximum: 59
	Default: 20
  -NPPC:               Points per Square
	floating point number
	Minimum: 1.000000
	Default: 5.000000
  -K:                     Tolerance
	integer number
	Minimum: 0
	Default: 140