[GRASS-SVN] r51656 - in grass-addons/grass6/raster: . r.to.vect.lines

[svn_grass at osgeo.org]

Author: hamish
Date: 2012-05-20 02:52:29 -0700 (Sun, 20 May 2012)
New Revision: 51656

Added:
   grass-addons/grass6/raster/r.to.vect.lines/
   grass-addons/grass6/raster/r.to.vect.lines/description.html
   grass-addons/grass6/raster/r.to.vect.lines/r.to.vect.lines.py
Log:
experimental python module that samples raster rows and turns them into 3D vector lines (e.g. for wiggle plots)

Added: grass-addons/grass6/raster/r.to.vect.lines/description.html
===================================================================
--- grass-addons/grass6/raster/r.to.vect.lines/description.html	                        (rev 0)
+++ grass-addons/grass6/raster/r.to.vect.lines/description.html	2012-05-20 09:52:29 UTC (rev 51656)
@@ -0,0 +1,49 @@
+<h2>NOTES</h2>
+
+Extracts rows from a raster map as 3D vector lines.
+<p>
+Reads a raster map, writes to a vector map.
+<p>
+Doesn't check if output map already exists. (fixme)
+<p>
+The category given to the line refers to the row number. (starting with category 0!)
+<p>
+Nulls within a row are skipped, so holes will be filled by a straight line. (fixme)
+Nulls at the ends of lines are not included in the output line.
+<p>
+Nulls are not handled very well and may sneak through as very negative numbers. (fixme)
+
+
+<h2>EXAMPLE</h2>
+
+Display a wiggle plot in NVIZ:
+<br>
+(Spearfish dataset)
+
+<div class="code"><pre>
+   g.region rast=elevation.dem
+   r.to.vect.lines.py in=elevation.dem out=wiggle_lines
+   eval `v.info -g wiggle_lines`
+   r.mapcalc "floor = $bottom"
+   nviz elev=floor vector=wiggle_lines
+</pre></div>
+
+
+<h2>SEE ALSO</h2>
+
+<em>
+<a href="r.to.vect.html">r.to.vect</a><br>
+<a href="v.in.lines.html">v.in.lines</a><br>
+</em>
+
+
+<h2>AUTHOR</h2>
+
+Hamish Bowman<br>
+<i>
+Dept. of Geology<br>
+University of Otago<br>
+Dunedin, New Zealand</i>
+
+<p>
+<i>Last changed: $Date$</i>


Property changes on: grass-addons/grass6/raster/r.to.vect.lines/description.html
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Added: svn:mime-type
   + text/html
Added: svn:keywords
   + Author Date Id
Added: svn:eol-style
   + native

Added: grass-addons/grass6/raster/r.to.vect.lines/r.to.vect.lines.py
===================================================================
--- grass-addons/grass6/raster/r.to.vect.lines/r.to.vect.lines.py	                        (rev 0)
+++ grass-addons/grass6/raster/r.to.vect.lines/r.to.vect.lines.py	2012-05-20 09:52:29 UTC (rev 51656)
@@ -0,0 +1,183 @@
+#!/usr/bin/env python
+############################################################################
+#
+# MODULE:       r.to.vect.lines
+# AUTHOR(S):    Hamish Bowman, Dunedin, New Zealand
+# PURPOSE:      Extracts wiggle lines from raster data for use with e.g. NVIZ
+# COPYRIGHT:    (C) 2012 by Hamish Bowman, and the GRASS Development Team
+#
+#               This program is free software under the GNU General
+#               Public License (>=v2). Read the file COPYING that
+#               comes with GRASS for details.
+#
+#############################################################################
+#
+# To make a wiggle line plot in NVIZ:
+#   g.region rast=elevation.dem
+#   r.to.vect.lines.py in=elevation.dem out=wiggle_lines
+#   eval `v.info -g wiggle_lines`
+#   r.mapcalc "floor = $bottom"
+#   nviz elev=floor vector=wiggle_lines
+#
+
+#%module
+#% description: Convert raster rows to vector lines.
+#% keywords: raster, conversion, wiggles
+#%end
+#%option
+#% key: input
+#% type: string
+#% key_desc: name
+#% gisprompt: "old,cell,raster";
+#% required: yes
+#% description: Name of input raster map
+#%end
+#%option
+#% key: output
+#% type: string
+#% key_desc: name
+#% gisprompt: "new,vector,vector";
+#% required: yes
+#% description: Name for output vector map
+#%end
+#%option
+#% key: skip
+#% type: integer
+#% required: no
+#% description: Sample every Nth grid row
+#% answer: 10
+#% options: 1-100000
+#%end
+#%flag
+#% key: v
+#% description: Sample vertically (default is to sample horizontally)
+#%end
+
+import os
+import sys
+from grass.script import core as grass
+from grass.lib.gis import *
+from grass.lib.vector import *
+from ctypes import *
+
+# check if GRASS is running or not
+if not os.environ.has_key("GISBASE"):
+    sys.exit("You must be in GRASS GIS to run this program")
+
+
+def main():
+    G_gisinit(sys.argv[0])
+
+    inmap = options['input']
+    outmap = options['output']
+    skip = int(options['skip'])
+    go_vert = flags['v']
+
+    if go_vert:
+	sys.exit("Vertical lines are yet to do.")
+
+    ##### Query the region
+    region = Cell_head()
+    G_get_window(byref(region))
+
+    #### Raster map setup
+    # find raster map in search path
+    mapset = G_find_cell2(inmap, '')
+    if not mapset:
+        sys.exit("Raster map <%s> not found" % inmap)
+
+    # determine the inputmap type (CELL/FCELL/DCELL)
+    data_type = G_raster_map_type(inmap, mapset)
+
+    if data_type == CELL_TYPE:
+        ptype = POINTER(c_int)
+        type_name = 'CELL'
+    elif data_type == FCELL_TYPE:
+        ptype = POINTER(c_float)
+        type_name = 'FCELL'
+    elif data_type == DCELL_TYPR:
+        ptype = POINTER(c_double)
+        type_name = 'DCELL'
+
+    #print "Raster map <%s> contains data type %s." % (inmap, type_name)
+
+    in_fd   = G_open_cell_old(inmap, mapset)
+    in_rast = G_allocate_raster_buf(data_type)
+    in_rast = cast(c_void_p(in_rast), ptype)
+
+    rows = G_window_rows()
+    cols = G_window_cols()
+    #print "Current region is %d rows x %d columns" % (rows, cols)
+
+
+    #### Vector map setup
+    # define map structure
+    map_info = pointer(Map_info())
+
+    # define open level (level 2: topology)
+    Vect_set_open_level(2)
+
+    # open new 3D vector map
+    Vect_open_new(map_info, outmap, True)
+
+    # Create and initialize structs to store points/lines and category numbers
+    Points = Vect_new_line_struct()
+    Cats = Vect_new_cats_struct()
+    fea_type = GV_LINE
+
+    LineArrayType = c_double * cols
+    xL = LineArrayType()
+    yL = LineArrayType()
+    zL = LineArrayType()
+
+
+    #### iterate through map rows
+    for row in xrange(rows):
+        if row % skip != 0:
+            continue
+
+        # read a row of raster data into memory, then print it
+        G_get_raster_row(in_fd, in_rast, row, data_type)
+        #print row, in_rast[0:cols]
+	#print row, in_rast[0:5]
+
+        # y-value
+        coor_row_static = G_row_to_northing((row + 0.5), byref(region))
+        # x-end nodes
+        #coor_col_min = G_col_to_easting((0 + 0.5), byref(region))
+	#coor_col_max = G_col_to_easting((cols - 0.5), byref(region))
+        #print '  ',coor_row_static,coor_col_min,coor_col_max
+
+        # reset
+	n = 0
+        for col in xrange(cols):
+	   xL[col] = yL[col] = zL[col] = 0
+
+        # TODO check for NULL
+        for col in xrange(cols):
+            #? howto if G_is_null_value(in_rast[col], data_type):
+            if in_rast[col] > -2e9:
+                xL[n] = G_col_to_easting((col + 0.5), byref(region))
+                yL[n] = coor_row_static
+                zL[n] = in_rast[col]
+		n = n + 1
+
+        #print valid_cols,n
+        Vect_cat_del(Cats, 1)
+        # beware if you care, this creates a cat 0
+        Vect_cat_set(Cats, 1, row)
+        Vect_reset_line(Points)
+        Vect_copy_xyz_to_pnts(Points, xL, yL, zL, n)
+        Vect_write_line(map_info, fea_type, Points, Cats)
+
+
+    # Build topology for vector map and close them all
+    Vect_build(map_info)
+    Vect_close(map_info)
+    G_close_cell(in_fd)
+    G_done_msg('')
+
+
+if __name__ == "__main__":
+    options, flags = grass.parser()
+    main()


Property changes on: grass-addons/grass6/raster/r.to.vect.lines/r.to.vect.lines.py
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Added: svn:executable
   + *
Added: svn:mime-type
   + text/x-python
Added: svn:eol-style
   + native