
NAME
v.surf.bspline - Bicubic or bilineal interpolation with Tykhonov regularization
KEYWORDS
vector, interpolation
SYNOPSIS
v.surf.bspline
v.surf.bspline help
v.surf.bspline input=name [input_ext=name] [output=name] [raster_out=name] [database=string] [driver=string] [sie=float] [sin=float] [type=string] [lambda_i=float] [--overwrite]
Flags:
- --overwrite
- Force overwrite of output files
Parameters:
- input=name
- Name of input vector map
- input_ext=name
- Name of input vector map of sparse points
- output=name
- Name of output vector map
- raster_out=name
- Name of output raster map
- database=string
- Database name
- driver=string
- Driver name
- Options: dbf,odbc,pg,mysql,ogr
- sie=float
- Interpolation spline step value in east direction
- Default: 4
- sin=float
- Interpolation spline step value in north direction
- Default: 4
- type=string
- Spline type of interpolation
- Options: bilinear,bicubic
- Default: bilinear
- lambda_i=float
- Thychonov regularization weigth
- Default: 1
DESCRIPTION
v.surf.bspline makes a bilinear/bicubic interpolation with
Tykhonov regularization. The required input is a vector of only
points that will be used for interpolate a reference surface. If an
extra input vector is used, an estimation using the reference surface
will be done on the points of this last vector. In other case, the
interpolation will be done with the points of the former vector. The
output format can be a vector in which case the interpolation will be
done on the sparse points, or a raster map. In this last case, the
interpolation will be on a regular grid.
EXAMPLES
Basic interpolation
v.surf.bspline input=point_vector output=interpolate_surface type=bicubic
In this case, a bicubic spline interpolation will be done and an
estimation of the points of vector will be the output.
Basic interpolation and raster output with a long spline step
v.surf.bspline input=point_vector raster_out=interpolate_surface sie=25 sin=25
Now, a bilinear spline interpolation will be done on a grid.
Estimation on sparse points
v.surf.bspline input=point_vector int_ext=sparse_points output=interpolate_surface
In this last case, an estimation of the point within sparse points
will be done using the parameters estimated with the points of
point_vector.
AUTHORS
Original version of the program in GRASS 5.4: (s.bspline.reg)
Maria Antonia Brovelli, Massimiliano Cannata, Ulisse Longoni, Mirko Reguzzoni
Updates for GRASS 6:
Roberto Antolin
Last changed: $Date: 2006/09/05 02:59:46 $
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