# -*- coding: utf-8 -*- """ *************************************************************************** HypsometricCurves.py --------------------- Date : November 2014 Copyright : (C) 2014 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__ = 'November 2014' __copyright__ = '(C) 2014, Alexander Bruy' # This will get replaced with a git SHA1 when you do a git archive __revision__ = '$Format:%H$' import os import numpy import csv from osgeo import gdal, ogr, osr from qgis.core import (QgsRectangle, QgsGeometry, QgsFeatureRequest, QgsProcessing, QgsProcessingParameterBoolean, QgsProcessingParameterNumber, QgsProcessingParameterRasterLayer, QgsProcessingParameterFeatureSource, QgsProcessingParameterFolderDestination) from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm from processing.tools import raster class HypsometricCurves(QgisAlgorithm): INPUT_DEM = 'INPUT_DEM' BOUNDARY_LAYER = 'BOUNDARY_LAYER' STEP = 'STEP' USE_PERCENTAGE = 'USE_PERCENTAGE' OUTPUT_DIRECTORY = 'OUTPUT_DIRECTORY' def group(self): return self.tr('Raster terrain analysis') def groupId(self): return 'rasterterrainanalysis' def __init__(self): super().__init__() def initAlgorithm(self, config=None): self.addParameter(QgsProcessingParameterRasterLayer(self.INPUT_DEM, self.tr('DEM to analyze'))) self.addParameter(QgsProcessingParameterFeatureSource(self.BOUNDARY_LAYER, self.tr('Boundary layer'), [QgsProcessing.TypeVectorPolygon])) self.addParameter(QgsProcessingParameterNumber(self.STEP, self.tr('Step'), type=QgsProcessingParameterNumber.Double, minValue=0.0, maxValue=999999999.999999, defaultValue=100.0)) self.addParameter(QgsProcessingParameterBoolean(self.USE_PERCENTAGE, self.tr('Use % of area instead of absolute value'), defaultValue=False)) self.addParameter(QgsProcessingParameterFolderDestination(self.OUTPUT_DIRECTORY, self.tr('Hypsometric curves'))) def name(self): return 'hypsometriccurves' def displayName(self): return self.tr('Hypsometric curves') def processAlgorithm(self, parameters, context, feedback): raster_layer = self.parameterAsRasterLayer(parameters, self.INPUT_DEM, context) target_crs = raster_layer.crs() rasterPath = raster_layer.source() source = self.parameterAsSource(parameters, self.BOUNDARY_LAYER, context) step = self.parameterAsDouble(parameters, self.STEP, context) percentage = self.parameterAsBool(parameters, self.USE_PERCENTAGE, context) outputPath = self.parameterAsString(parameters, self.OUTPUT_DIRECTORY, context) rasterDS = gdal.Open(rasterPath, gdal.GA_ReadOnly) geoTransform = rasterDS.GetGeoTransform() rasterBand = rasterDS.GetRasterBand(1) noData = rasterBand.GetNoDataValue() cellXSize = abs(geoTransform[1]) cellYSize = abs(geoTransform[5]) rasterXSize = rasterDS.RasterXSize rasterYSize = rasterDS.RasterYSize rasterBBox = QgsRectangle(geoTransform[0], geoTransform[3] - cellYSize * rasterYSize, geoTransform[0] + cellXSize * rasterXSize, geoTransform[3]) rasterGeom = QgsGeometry.fromRect(rasterBBox) crs = osr.SpatialReference() crs.ImportFromProj4(str(target_crs.toProj4())) memVectorDriver = ogr.GetDriverByName('Memory') memRasterDriver = gdal.GetDriverByName('MEM') features = source.getFeatures(QgsFeatureRequest().setDestinationCrs(target_crs, context.transformContext())) total = 100.0 / source.featureCount() if source.featureCount() else 0 for current, f in enumerate(features): if not f.hasGeometry(): continue if feedback.isCanceled(): break geom = f.geometry() intersectedGeom = rasterGeom.intersection(geom) if intersectedGeom.isEmpty(): feedback.pushInfo( self.tr('Feature {0} does not intersect raster or ' 'entirely located in NODATA area').format(f.id())) continue fName = os.path.join( outputPath, 'hystogram_%s_%s.csv' % (source.sourceName(), f.id())) ogrGeom = ogr.CreateGeometryFromWkt(intersectedGeom.asWkt()) bbox = intersectedGeom.boundingBox() xMin = bbox.xMinimum() xMax = bbox.xMaximum() yMin = bbox.yMinimum() yMax = bbox.yMaximum() (startColumn, startRow) = raster.mapToPixel(xMin, yMax, geoTransform) (endColumn, endRow) = raster.mapToPixel(xMax, yMin, geoTransform) width = endColumn - startColumn height = endRow - startRow srcOffset = (startColumn, startRow, width, height) srcArray = rasterBand.ReadAsArray(*srcOffset) if srcOffset[2] == 0 or srcOffset[3] == 0: feedback.pushInfo( self.tr('Feature {0} is smaller than raster ' 'cell size').format(f.id())) continue newGeoTransform = ( geoTransform[0] + srcOffset[0] * geoTransform[1], geoTransform[1], 0.0, geoTransform[3] + srcOffset[1] * geoTransform[5], 0.0, geoTransform[5] ) memVDS = memVectorDriver.CreateDataSource('out') memLayer = memVDS.CreateLayer('poly', crs, ogr.wkbPolygon) ft = ogr.Feature(memLayer.GetLayerDefn()) ft.SetGeometry(ogrGeom) memLayer.CreateFeature(ft) ft.Destroy() rasterizedDS = memRasterDriver.Create('', srcOffset[2], srcOffset[3], 1, gdal.GDT_Byte) rasterizedDS.SetGeoTransform(newGeoTransform) gdal.RasterizeLayer(rasterizedDS, [1], memLayer, burn_values=[1]) rasterizedArray = rasterizedDS.ReadAsArray() srcArray = numpy.nan_to_num(srcArray) masked = numpy.ma.MaskedArray(srcArray, mask=numpy.logical_or(srcArray == noData, numpy.logical_not(rasterizedArray))) self.calculateHypsometry(f.id(), fName, feedback, masked, cellXSize, cellYSize, percentage, step) memVDS = None rasterizedDS = None feedback.setProgress(int(current * total)) rasterDS = None return {self.OUTPUT_DIRECTORY: outputPath} def calculateHypsometry(self, fid, fName, feedback, data, pX, pY, percentage, step): out = dict() d = data.compressed() if d.size == 0: feedback.pushInfo( self.tr('Feature {0} does not intersect raster or ' 'entirely located in NODATA area').format(fid)) return minValue = d.min() maxValue = d.max() startValue = minValue tmpValue = minValue + step while startValue < maxValue: out[tmpValue] = ((startValue <= d) & (d < tmpValue)).sum() startValue = tmpValue tmpValue += step if percentage: multiplier = 100.0 / len(d.flat) else: multiplier = pX * pY for k, v in list(out.items()): out[k] = v * multiplier prev = None for i in sorted(out.items()): if prev is None: out[i[0]] = i[1] else: out[i[0]] = i[1] + out[prev] prev = i[0] with open(fName, 'w', newline='', encoding='utf-8') as out_file: writer = csv.writer(out_file) writer.writerow([self.tr('Area'), self.tr('Elevation')]) for i in sorted(out.items()): writer.writerow([i[1], i[0]])