def accept(self):
"""Do raster reclassification and display it in QGIS
.. versionadded: 3.4
:return:
"""
registry = QgsMapLayerRegistry.instance()
try:
index = self.cbo_raster_input.currentIndex()
layer_id = self.cbo_raster_input.itemData(
index, QtCore.Qt.UserRole)
layer = registry.mapLayer(layer_id)
class_attribute = 'class'
# extract thresholds
thresholds_list = self.thresholds_widget.get_parameter().value
thresholds_list.append(None)
ranges = ranges_according_thresholds_list(thresholds_list)
path = reclassify_polygonize(
layer.source(), ranges, name_field=class_attribute)
# load layer to QGIS
title = self.tr('%s classified') % self.tr(layer.name())
layer = QgsVectorLayer(path, title, 'ogr')
registry.addMapLayer(layer)
except Exception as e:
LOGGER.exception(e)
QtGui.qApp.setOverrideCursor(QtGui.QCursor(QtCore.Qt.WaitCursor))
self.disable_busy_cursor()
self.done(QDialog.Accepted)
def test_reclassify_polygonize(self):
"""Test if we can reclassify a raster according to some thresholds."""
raster_path = standard_data_path('hazard',
'continuous_flood_20_20.asc')
ranges = OrderedDict()
# value <= 0.2
ranges[1] = [None, 0.2]
# 0.2 < value <= 1
ranges[2] = [0.2, 1]
# 1 < value <= 1.3 and gap in output classes
ranges[10] = [1, 1.3]
# value > 1.3
ranges[11] = [1.3, None]
output = reclassify_polygonize(raster_path, ranges)
layer = QgsVectorLayer(output, 'test layer', 'ogr')
self.assertEqual(layer.featureCount(), 61)
expression = '"DN" = \'%s\'' % 1
request = QgsFeatureRequest().setFilterExpression(expression)
self.assertEqual(sum(1 for _ in layer.getFeatures(request)), 20)
expression = '"DN" = \'%s\'' % 2
request = QgsFeatureRequest().setFilterExpression(expression)
self.assertEqual(sum(1 for _ in layer.getFeatures(request)), 1)
expression = '"DN" = \'%s\'' % 10
request = QgsFeatureRequest().setFilterExpression(expression)
self.assertEqual(sum(1 for _ in layer.getFeatures(request)), 20)
expression = '"DN" = \'%s\'' % 11
request = QgsFeatureRequest().setFilterExpression(expression)
self.assertEqual(sum(1 for _ in layer.getFeatures(request)), 20)
def test_reclassify_polygonize(self):
"""Test if we can reclassify a raster according to some thresholds."""
raster_path = standard_data_path(
'hazard', 'continuous_flood_20_20.asc')
ranges = OrderedDict()
# value <= 0.2
ranges[1] = [None, 0.2]
# 0.2 < value <= 1
ranges[2] = [0.2, 1]
# 1 < value <= 1.3 and gap in output classes
ranges[10] = [1, 1.3]
# value > 1.3
ranges[11] = [1.3, None]
output = reclassify_polygonize(raster_path, ranges)
layer = QgsVectorLayer(output, 'test layer', 'ogr')
self.assertEqual(layer.featureCount(), 61)
expression = '"DN" = \'%s\'' % 1
request = QgsFeatureRequest().setFilterExpression(expression)
self.assertEqual(sum(1 for _ in layer.getFeatures(request)), 20)
expression = '"DN" = \'%s\'' % 2
request = QgsFeatureRequest().setFilterExpression(expression)
self.assertEqual(sum(1 for _ in layer.getFeatures(request)), 1)
expression = '"DN" = \'%s\'' % 10
request = QgsFeatureRequest().setFilterExpression(expression)
self.assertEqual(sum(1 for _ in layer.getFeatures(request)), 20)
expression = '"DN" = \'%s\'' % 11
request = QgsFeatureRequest().setFilterExpression(expression)
self.assertEqual(sum(1 for _ in layer.getFeatures(request)), 20)
def run(self):
"""Run the impact function.
:returns: A vector layer with affected areas marked.
:type: safe_layer
"""
hazard_layer = self.hazard.layer
exposure = self.exposure.layer
# Thresholds for tsunami hazard zone breakdown.
group_parameters = self.parameters['group_threshold']
ver_low_unit = group_parameters.value_map['very_low_threshold'].unit
unit_abbrev = ver_low_unit.abbreviation
unaffected_threshold = group_parameters.value_map[
'unaffected_threshold']
unaffected_max = unaffected_threshold.value
very_low_max = group_parameters.value_map['very_low_threshold'].value
low_max = group_parameters.value_map['low_threshold'].value
medium_max = group_parameters.value_map['moderate_threshold'].value
high_max = group_parameters.value_map['high_threshold'].value
ranges = ranges_according_thresholds_list(
[unaffected_max, very_low_max, low_max,
medium_max, high_max, None])
hazard_value_to_class = {}
for i, interval in enumerate(ranges):
hazard_value_to_class[interval] = self.hazard_classes[i]
# Get parameters from layer's keywords
class_field = self.exposure.keyword('field')
# reproject self.extent to the hazard projection
hazard_crs = hazard_layer.crs()
hazard_authid = hazard_crs.authid()
if hazard_authid == 'EPSG:4326':
viewport_extent = self.requested_extent
else:
geo_crs = QgsCoordinateReferenceSystem()
geo_crs.createFromSrid(4326)
viewport_extent = extent_to_geo_array(
QgsRectangle(*self.requested_extent), geo_crs, hazard_crs)
small_raster = align_clip_raster(hazard_layer, viewport_extent)
# Create vector features from the flood raster
hazard_class_attribute = 'hazard'
vector_file_path = reclassify_polygonize(
small_raster.source(), ranges, name_field=hazard_class_attribute)
hazard = QgsVectorLayer(vector_file_path, 'ash vector', 'ogr')
# prepare objects for re-projection of geometries
crs_wgs84 = QgsCoordinateReferenceSystem('EPSG:4326')
hazard_to_exposure = QgsCoordinateTransform(
hazard.crs(), exposure.crs())
wgs84_to_hazard = QgsCoordinateTransform(
crs_wgs84, hazard.crs())
wgs84_to_exposure = QgsCoordinateTransform(
crs_wgs84, exposure.crs())
extent = QgsRectangle(
self.requested_extent[0], self.requested_extent[1],
self.requested_extent[2], self.requested_extent[3])
extent_hazard = wgs84_to_hazard.transformBoundingBox(extent)
extent_exposure = wgs84_to_exposure.transformBoundingBox(extent)
extent_exposure_geom = QgsGeometry.fromRect(extent_exposure)
# make spatial index of hazard
hazard_index = QgsSpatialIndex()
hazard_features = {}
for f in hazard.getFeatures(QgsFeatureRequest(extent_hazard)):
f.geometry().transform(hazard_to_exposure)
hazard_index.insertFeature(f)
hazard_features[f.id()] = QgsFeature(f)
# create impact layer
filename = unique_filename(suffix='.shp')
impact_fields = exposure.dataProvider().fields()
impact_fields.append(QgsField(self.target_field, QVariant.String))
writer = QgsVectorFileWriter(
filename, 'utf-8', impact_fields, QGis.WKBPolygon, exposure.crs())
# iterate over all exposure polygons and calculate the impact
_calculate_landcover_impact(
exposure, extent_exposure, extent_exposure_geom,
hazard_class_attribute, hazard_features, hazard_index,
hazard_value_to_class, impact_fields, writer)
del writer
impact_layer = QgsVectorLayer(filename, 'Impacted Land Cover', 'ogr')
if impact_layer.featureCount() == 0:
raise ZeroImpactException()
zone_field = None
if self.aggregator:
zone_field = self.aggregator.exposure_aggregation_field
impact_data = LandCoverReportMixin(
question=self.question,
impact_layer=impact_layer,
target_field=self.target_field,
ordered_columns=self.hazard_classes,
affected_columns=self.affected_hazard_columns,
land_cover_field=class_field,
zone_field=zone_field
).generate_data()
# Define style for the impact layer
style_classes = [
dict(
label=self.hazard_classes[0] + ': %.1f - %.1f %s' % (
unaffected_max, very_low_max, unit_abbrev),
value=self.hazard_classes[0],
colour='#2C6BA4',
border_color='#000000',
transparency=0),
dict(
label=self.hazard_classes[1] + ': %.1f - %.1f %s' % (
very_low_max + 0.1, low_max, unit_abbrev),
value=self.hazard_classes[1],
colour='#00A4D8',
border_color='#000000',
transparency=0),
dict(
label=self.hazard_classes[2] + ': %.1f - %.1f %s' % (
low_max + 0.1, medium_max, unit_abbrev),
value=self.hazard_classes[2],
colour='#FFEF36',
border_color='#000000',
transparency=0),
dict(
label=self.hazard_classes[3] + ': %.1f - %.1f %s' % (
medium_max + 0.1, high_max, unit_abbrev),
value=self.hazard_classes[3],
colour='#EFA951',
border_color='#000000',
transparency=0),
dict(
label=self.hazard_classes[4] + ': > %.1f %s' % (
high_max, unit_abbrev),
value=self.hazard_classes[4],
colour='#d62631',
border_color='#000000',
transparency=0),
]
style_info = dict(
target_field=self.target_field,
style_classes=style_classes,
style_type='categorizedSymbol')
extra_keywords = {
'map_title': self.metadata().key('map_title'),
'target_field': self.target_field
}
impact_layer_keywords = self.generate_impact_keywords(extra_keywords)
# Create vector layer and return
impact_layer = Vector(
data=impact_layer,
name=self.metadata().key('layer_name'),
keywords=impact_layer_keywords,
style_info=style_info)
impact_layer.impact_data = impact_data
self._impact = impact_layer
return impact_layer
def run(self):
"""Run the impact function.
:returns: A vector layer with affected areas marked.
:type: safe_layer
"""
hazard_layer = self.hazard.layer
exposure = self.exposure.layer
# Thresholds for tsunami hazard zone breakdown.
low_max = self.parameters['low_threshold'].value
medium_max = self.parameters['medium_threshold'].value
high_max = self.parameters['high_threshold'].value
ranges = ranges_according_thresholds(low_max, medium_max, high_max)
hazard_value_to_class = {}
for i, interval in enumerate(ranges):
hazard_value_to_class[interval] = self.hazard_classes[i]
# Get parameters from layer's keywords
class_field = self.exposure.keyword('field')
# reproject self.extent to the hazard projection
hazard_crs = hazard_layer.crs()
hazard_authid = hazard_crs.authid()
if hazard_authid == 'EPSG:4326':
viewport_extent = self.requested_extent
else:
geo_crs = QgsCoordinateReferenceSystem()
geo_crs.createFromSrid(4326)
viewport_extent = extent_to_geo_array(
QgsRectangle(*self.requested_extent), geo_crs, hazard_crs)
small_raster = align_clip_raster(hazard_layer, viewport_extent)
# Create vector features from the flood raster
hazard_class_attribute = 'hazard'
vector_file_path = reclassify_polygonize(
small_raster.source(), ranges, name_field=hazard_class_attribute)
hazard = QgsVectorLayer(vector_file_path, 'tsunami', 'ogr')
# prepare objects for re-projection of geometries
crs_wgs84 = QgsCoordinateReferenceSystem('EPSG:4326')
hazard_to_exposure = QgsCoordinateTransform(
hazard.crs(), exposure.crs())
wgs84_to_hazard = QgsCoordinateTransform(
crs_wgs84, hazard.crs())
wgs84_to_exposure = QgsCoordinateTransform(
crs_wgs84, exposure.crs())
extent = QgsRectangle(
self.requested_extent[0], self.requested_extent[1],
self.requested_extent[2], self.requested_extent[3])
extent_hazard = wgs84_to_hazard.transformBoundingBox(extent)
extent_exposure = wgs84_to_exposure.transformBoundingBox(extent)
extent_exposure_geom = QgsGeometry.fromRect(extent_exposure)
# make spatial index of hazard
hazard_index = QgsSpatialIndex()
hazard_features = {}
for f in hazard.getFeatures(QgsFeatureRequest(extent_hazard)):
f.geometry().transform(hazard_to_exposure)
hazard_index.insertFeature(f)
hazard_features[f.id()] = QgsFeature(f)
# create impact layer
filename = unique_filename(suffix='.shp')
impact_fields = exposure.dataProvider().fields()
impact_fields.append(QgsField(self.target_field, QVariant.String))
writer = QgsVectorFileWriter(
filename, 'utf-8', impact_fields, QGis.WKBPolygon, exposure.crs())
# iterate over all exposure polygons and calculate the impact
_calculate_landcover_impact(
exposure, extent_exposure, extent_exposure_geom,
hazard_class_attribute, hazard_features, hazard_index,
hazard_value_to_class, impact_fields, writer)
del writer
impact_layer = QgsVectorLayer(filename, 'Impacted Land Cover', 'ogr')
if impact_layer.featureCount() == 0:
raise ZeroImpactException()
zone_field = None
if self.aggregator:
zone_field = self.aggregator.exposure_aggregation_field
impact_data = LandCoverReportMixin(
question=self.question,
impact_layer=impact_layer,
target_field=self.target_field,
ordered_columns=self.hazard_classes,
affected_columns=self.affected_hazard_columns,
land_cover_field=class_field,
zone_field=zone_field
).generate_data()
# Define style for the impact layer
style_classes = [
dict(
label=self.hazard_classes[0] + ': 0m',
value=self.hazard_classes[0],
colour='#00FF00',
border_color='#000000',
transparency=0),
dict(
label=self.hazard_classes[1] + ': >0 - %.1f m' % low_max,
value=self.hazard_classes[1],
colour='#FFFF00',
border_color='#000000',
transparency=0),
dict(
label=self.hazard_classes[2] + ': %.1f - %.1f m' % (
low_max + 0.1, medium_max),
value=self.hazard_classes[2],
colour='#FFB700',
border_color='#000000',
transparency=0),
dict(
label=self.hazard_classes[3] + ': %.1f - %.1f m' % (
medium_max + 0.1, high_max),
value=self.hazard_classes[3],
colour='#FF6F00',
border_color='#000000',
transparency=0),
dict(
label=self.hazard_classes[4] + ' > %.1f m' % high_max,
value=self.hazard_classes[4],
colour='#FF0000',
border_color='#000000',
transparency=0),
]
style_info = dict(
target_field=self.target_field,
style_classes=style_classes,
style_type='categorizedSymbol')
extra_keywords = {
'map_title': self.map_title(),
'target_field': self.target_field
}
impact_layer_keywords = self.generate_impact_keywords(extra_keywords)
# Create vector layer and return
impact_layer = Vector(
data=impact_layer,
name=self.map_title(),
keywords=impact_layer_keywords,
style_info=style_info)
impact_layer.impact_data = impact_data
self._impact = impact_layer
return impact_layer