SAGA 9.4.2 | 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, optional, CMDTARGET_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
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_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_FITS:   	Fit
	choice
	Available Choices:
	[0] nodes
	[1] cells
	Default: 0
  -TARGET_TEMPLATE:    	Target System
	grid, input, optional, CMD
  -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