1r3.out.ascii(1) GRASS GIS User's Manual r3.out.ascii(1)
2
6 r3.out.ascii - Converts a 3D raster map layer into a ASCII text file.
7
9 raster3d, export, output, voxel, conversion, ASCII
10
12 r3.out.ascii
13 r3.out.ascii --help
14 r3.out.ascii [-hrdcm] input=string [output=name] [precision=integer]
15 [null_value=string] [--overwrite] [--help] [--verbose] [--quiet]
16 [--ui]
17 Flags:
19 -h
20 Suppress printing of header information
21 -r
23 Switch the row order in output from north->south to south->north
24 -d
26 Switch the depth order in output from bottom->top to top->bottom
27 -c
29 Print grass6 compatible format. Flags -d and -r are ignored.
30 -m
32 Use 3D raster mask (if exists) with input map
33 --overwrite
35 Allow output files to overwrite existing files
36 --help
38 Print usage summary
39 --verbose
41 Verbose module output
42 --quiet
44 Quiet module output
45 --ui
47 Force launching GUI dialog
48 Parameters:
50 input=string [required]
51 3D raster map to be converted to ASCII
52 output=name
54 Name for ASCII output file
55 precision=integer
57 Number of decimal places for floats
58 Options: 0-20
59 Default: 8
60 null_value=string
62 String representing NULL value
63 Default: *
64
66 r3.out.ascii exports a 3D raster map in ASCII format. The input parame‐
67 ter is a valid 3D raster map in the current mapset search path. The
68 output parameter is the name of an ASCII file which will be written in
69 the current working directory.
70 If output is not specified then standard output (stdout) is used. The
72 -h flag may be used to suppress header information. The module is sen‐
73 sitive to region settings (set with g.region).
74 The -c flag will create GRASS 6 r3.in.ascii compatible output.
76
78 The default format of the exported ASCII file is equivalent to that re‐
79 quired by r3.in.ascii. In particular, files output by r3.out.ascii with
80 header information may be converted back to 3D raster maps with
81 r3.in.ascii.
82 The format of the ASCII file is:
84 version: "grass7"
85 order: "nsbt" or "nstb" or "snbt" or "sntb"
86 north: floating point
87 south: floating point
88 east: floating point
89 west: floating point
90 top: floating point
91 bottom: floating point
92 rows: integer
93 cols: integer
94 levels: integer
95 The version and order options have been introduced in GRASS 7 in June
96 2011. The order option describes the order of rows and depths in the
97 output. It is possible to create output of different row order using
98 the -r flag and output of different depths order using the -d flag.
99 The default order is:
100 west -> east for columns
102 north -> south for rows
103 bottom -> top for depths
104 This header is followed by the cell values in floating point format or‐
106 ganized in rows with constant col and level coordinate. The rows are
107 organized by constant level coordinate. Individual cell values are sep‐
108 arated by space or CR. Cell values are exported as a series of hori‐
109 zontal slices in row-major order. The data starts with the upper left
110 corner (NW) at the bottom of the data set. The values at the following
111 coordinates are exported:
112 (x, y + rows, z) (x + 1, y + rows, z) ... (x + cols, y + rows, z)
113 (x, y + rows, z) (x + 1, y + rows - 1, z) ... (x + cols, y + rows - 1, z)
114 . . .
115 . . .
116 . . .
117 (x, y, z + depths) (x + 1, y, z + depths) ... (x + cols, y, z + depths)
118 This order is compatible with the r.in.ascii row -> column ordering.
119 Supported orders are:
121 • nsbt: north -> south and bottom -> top ordering which is the
123 default (no flags)
124 • snbt: south -> north and bottom -> top ordering using -r flag
126 • nstb: north -> south and top -> bottom ordering using -d flag
128 • sntb: south -> north and top -> bottom ordering using -rd flag
130 The internal storage scheme of 3D raster maps is visualized in the fol‐
132 lowing picture:
133 The coordinate system and tile layout of a voxel map in
136 GRASS
137 One level maps can be imported with r.in.ascii (2D raster) using the
140 default nsbt order and removing the header lines "version", "order",
141 "top", "bottom" and "levels".
142
144 We define a small region with 4 columns, 3 rows and 2 depths (4x3x2)
145 and export it using different ordering definitions:
146 g.region res3=1 t=2 b=0 w=0 e=4 s=0 n=3
147 r3.mapcalc "simple_example = row() + col() + depth()"
148 Default order:
149 r3.out.ascii input=simple_example dp=0
150 version: grass7
151 order: nsbt
152 north: 3.000000
153 south: 0.000000
154 east: 4.000000
155 west: 0.000000
156 top: 2.000000
157 bottom: 0.000000
158 rows: 3
159 cols: 4
160 levels: 2
161 3 4 5 6
162 4 5 6 7
163 5 6 7 8
164 4 5 6 7
165 5 6 7 8
166 6 7 8 9
167 Inverse row order (-r)
168 r3.out.ascii input=simple_example dp=0 -r
169 version: grass7
170 order: snbt
171 north: 3.000000
172 south: 0.000000
173 east: 4.000000
174 west: 0.000000
175 top: 2.000000
176 bottom: 0.000000
177 rows: 3
178 cols: 4
179 levels: 2
180 5 6 7 8
181 4 5 6 7
182 3 4 5 6
183 6 7 8 9
184 5 6 7 8
185 4 5 6 7
186 Inverse depth order (-d)
187 r3.out.ascii input=simple_example dp=0 -d
188 version: grass7
189 order: nstb
190 north: 3.000000
191 south: 0.000000
192 east: 4.000000
193 west: 0.000000
194 top: 2.000000
195 bottom: 0.000000
196 rows: 3
197 cols: 4
198 levels: 2
199 4 5 6 7
200 5 6 7 8
201 6 7 8 9
202 3 4 5 6
203 4 5 6 7
204 5 6 7 8
205 Inverse row and depth order (-rd)
206 r3.out.ascii input=simple_example dp=0 -rd
207 version: grass7
208 order: sntb
209 north: 3.000000
210 south: 0.000000
211 east: 4.000000
212 west: 0.000000
213 top: 2.000000
214 bottom: 0.000000
215 rows: 3
216 cols: 4
217 levels: 2
218 6 7 8 9
219 5 6 7 8
220 4 5 6 7
221 5 6 7 8
222 4 5 6 7
223 3 4 5 6
224
226 r3.in.ascii, r.out.ascii, g.region
227
229 Roman Waupotitsch, Michael Shapiro, Helena Mitasova, Bill Brown, Lubos
230 Mitas, Jaro Hofierka, Sören Gebbert
231
233 Available at: r3.out.ascii source code (history)
234 Accessed: Saturday Jan 21 20:39:36 2023
236 Main index | 3D raster index | Topics index | Keywords index | Graphi‐
238 cal index | Full index
239 © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
241GRASS 8.2.1 r3.out.ascii(1)