[processing] add gdal slope algorithm (addresses #7201)

alexbruy · alexbruy · commit e6ba40585cde · 2013-10-13T16:39:14.000+03:00
diff --git a/python/plugins/processing/gdal/GdalOgrAlgorithmProvider.py b/python/plugins/processing/gdal/GdalOgrAlgorithmProvider.py
@@ -55,6 +55,7 @@
 from processing.gdal.extractprojection import ExtractProjection
 from processing.gdal.gdal2xyz import gdal2xyz
 from processing.gdal.hillshade import hillshade
+from processing.gdal.slope import slope
 
 from processing.gdal.ogr2ogr import Ogr2Ogr
 from processing.gdal.ogrinfo import OgrInfo
@@ -106,7 +107,7 @@ def createAlgsList(self):
             rgb2pct(), pct2rgb(), merge(), polygonize(), gdaladdo(),
             ClipByExtent(), ClipByMask(), contour(), rasterize(), proximity(),
             sieve(), fillnodata(), ExtractProjection(), gdal2xyz(),
-            hillshade(),
+            hillshade(), slope(),
             # ----- OGR tools -----
             OgrInfo(), Ogr2Ogr(), OgrSql(),
             ]
diff --git a/python/plugins/processing/gdal/slope.py b/python/plugins/processing/gdal/slope.py
@@ -0,0 +1,94 @@
+# -*- coding: utf-8 -*-
+
+"""
+***************************************************************************
+    slope.py
+    ---------------------
+    Date                 : October 2013
+    Copyright            : (C) 2013 by Alexander Bruy
+    Email                : alexander dot bruy at gmail dot com
+***************************************************************************
+*                                                                         *
+*   This program is free software; you can redistribute it and/or modify  *
+*   it under the terms of the GNU General Public License as published by  *
+*   the Free Software Foundation; either version 2 of the License, or     *
+*   (at your option) any later version.                                   *
+*                                                                         *
+***************************************************************************
+"""
+
+__author__ = 'Alexander Bruy'
+__date__ = 'October 2013'
+__copyright__ = '(C) 2013, Alexander Bruy'
+
+# This will get replaced with a git SHA1 when you do a git archive
+
+__revision__ = '$Format:%H$'
+
+
+from PyQt4.QtGui import *
+
+from processing.core.GeoAlgorithm import GeoAlgorithm
+from processing.parameters.ParameterRaster import ParameterRaster
+from processing.parameters.ParameterBoolean import ParameterBoolean
+from processing.parameters.ParameterNumber import ParameterNumber
+from processing.outputs.OutputRaster import OutputRaster
+from processing.gdal.GdalUtils import GdalUtils
+from processing.tools.system import *
+
+
+class slope(GeoAlgorithm):
+
+    INPUT = 'INPUT'
+    BAND = 'BAND'
+    COMPUTE_EDGES = 'COMPUTE_EDGES'
+    ZEVENBERGEN = 'ZEVENBERGEN'
+    AS_PERCENT = 'AS_PERCENT'
+    SCALE = 'SCALE'
+    OUTPUT = 'OUTPUT'
+
+    #def getIcon(self):
+    #    filepath = os.path.dirname(__file__) + '/icons/dem.png'
+    #    return QIcon(filepath)
+
+    def defineCharacteristics(self):
+        self.name = 'Slope'
+        self.group = '[GDAL] Analysis'
+        self.addParameter(ParameterRaster(self.INPUT, 'Input layer'))
+        self.addParameter(ParameterNumber(self.BAND, 'Band number', 1, 99, 1))
+        self.addParameter(ParameterBoolean(self.COMPUTE_EDGES, 'Compute edges',
+                          False))
+        self.addParameter(ParameterBoolean(self.ZEVENBERGEN,
+                "Use Zevenbergen&Thorne formula (instead of the Horn's one)",
+                False))
+        self.addParameter(ParameterBoolean(self.AS_PERCENT,
+                          'Slope expressed as percent (instead of degrees)',
+                          False))
+        self.addParameter(ParameterNumber(self.SCALE,
+                          'Scale (ratio of vert. units to horiz.)', 0.0,
+                          99999999.999999, 1.0))
+
+        self.addOutput(OutputRaster(self.OUTPUT, 'Output file'))
+
+    def processAlgorithm(self, progress):
+        arguments = ['slope']
+        arguments.append(unicode(self.getParameterValue(self.INPUT)))
+        arguments.append(unicode(self.getOutputValue(self.OUTPUT)))
+
+        arguments.append('-b')
+        arguments.append(str(self.getParameterValue(self.BAND)))
+        arguments.append('-s')
+        arguments.append(str(self.getParameterValue(self.SCALE)))
+
+        if self.getParameterValue(self.COMPUTE_EDGES):
+            arguments.append('-compute_edges')
+
+        if self.getParameterValue(self.ZEVENBERGEN):
+            arguments.append('-alg')
+            arguments.append('ZevenbergenThorne')
+
+        if self.getParameterValue(self.AS_PERCENT):
+            arguments.append('-p')
+
+        GdalUtils.runGdal(['gdaldem',
+                          GdalUtils.escapeAndJoin(arguments)], progress)
