1r.resamp.interp(1)          GRASS GIS User's Manual         r.resamp.interp(1)
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NAME

6       r.resamp.interp   - Resamples raster map to a finer grid using interpo‐
7       lation.
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KEYWORDS

10       raster, resample, interpolation, nearest neighbor,  bilinear,  bicubic,
11       lanczos
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SYNOPSIS

14       r.resamp.interp
15       r.resamp.interp --help
16       r.resamp.interp input=name output=name  [method=string]   [--overwrite]
17       [--help]  [--verbose]  [--quiet]  [--ui]
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19   Flags:
20       --overwrite
21           Allow output files to overwrite existing files
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23       --help
24           Print usage summary
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26       --verbose
27           Verbose module output
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29       --quiet
30           Quiet module output
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32       --ui
33           Force launching GUI dialog
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35   Parameters:
36       input=name [required]
37           Name of input raster map
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39       output=name [required]
40           Name for output raster map
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42       method=string
43           Sampling interpolation method
44           Options: nearest, bilinear, bicubic, lanczos
45           Default: bilinear
46           nearest: Nearest-neighbor interpolation
47           bilinear: Bilinear interpolation
48           bicubic: Bicubic interpolation
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DESCRIPTION

51       r.resamp.interp resamples an input raster map by interpolating  between
52       the  neighboring cells via a selectable resampling algorithm. All cells
53       present in the neighborhood of the input raster cell must  be  non-null
54       to  generate a non-null cell in the output raster map. A choice of four
55       interpolation methods is available; each uses the weighted values of  a
56       different  number  of  adjacent cells in the input map to determine the
57       value of each cell in the output map as follows:
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59           ·   nearest neighbour (1 cell)
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61           ·   bilinear (4 cells)
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63           ·   bicubic (16 cells)
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65           ·   lanczos (25 cells)
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67       This module is intended for reinterpolation of  continuous  data  to  a
68       different  resolution rather than for interpolation from scattered data
69       (use the v.surf.* modules for that purpose).
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NOTES

72       Resampling  modules   (r.resample,   r.resamp.stats,   r.resamp.interp,
73       r.resamp.rst) resample the map to match the current region settings.
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75       Note that for bilinear, bicubic and lanczos interpolation, cells of the
76       output raster that cannot be bounded by the appropriate number of input
77       cell  centers  are set to NULL (NULL propagation). This could occur due
78       to the input cells being outside the  current  region,  being  NULL  or
79       MASKed.
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81       For  longitude-latitude locations, the interpolation algorithm is based
82       on degree fractions, not on the absolute distances  between  cell  cen‐
83       ters.   Any attempt to implement the latter would violate the integrity
84       of the interpolation method.
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EXAMPLE

87       Resample elevation raster map to a  higher  resolution  (from  500m  to
88       250m; North Carolina sample dataset):
89       g.region raster=elev_state_500m -p
90       g.region res=250 -ap
91       r.resamp.interp input=elev_state_500m output=elev_state_250m \
92                       method=bilinear
93       Original 500m resolution elevation map
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95       Resampled (bilinear) 250m resolution elevation map
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SEE ALSO

98        g.region, r.resample, r.resamp.filter, r.resamp.rst, r.resamp.stats
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100       Overview: Interpolation and Resampling in GRASS GIS
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AUTHOR

103       Glynn Clements
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SOURCE CODE

106       Available at: r.resamp.interp source code (history)
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108       Main  index  | Raster index | Topics index | Keywords index | Graphical
109       index | Full index
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111       © 2003-2020 GRASS Development Team, GRASS GIS 7.8.5 Reference Manual
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115GRASS 7.8.5                                                 r.resamp.interp(1)