def sum_fields(layer, output_field_key, input_fields):
"""Sum the value of input_fields and put it as output_field.
:param layer: The vector layer.
:type layer: QgsVectorLayer
:param output_field_key: The output field definition key.
:type output_field_key: basestring
:param input_fields: List of input fields' name.
:type input_fields: list
"""
field_definition = definition(output_field_key)
output_field_name = field_definition['field_name']
# If the fields only has one element
if len(input_fields) == 1:
# Name is different, copy it
if input_fields[0] != output_field_name:
to_rename = {input_fields[0]: output_field_name}
# We copy only, it will be deleted later.
# We can't rename the field, we need to copy it as the same
# field might be used many times in the FMT tool.
copy_fields(layer, to_rename)
else:
# Name is same, do nothing
return
else:
# Creating expression
# Put field name in a double quote. See #4248
input_fields = ['"%s"' % f for f in input_fields]
string_expression = ' + '.join(input_fields)
sum_expression = QgsExpression(string_expression)
context = QgsExpressionContext()
context.setFields(layer.pendingFields())
sum_expression.prepare(context)
# Get the output field index
output_idx = layer.fieldNameIndex(output_field_name)
# Output index is not found
if output_idx == -1:
output_field = create_field_from_definition(field_definition)
layer.startEditing()
layer.addAttribute(output_field)
layer.commitChanges()
output_idx = layer.fieldNameIndex(output_field_name)
layer.startEditing()
# Iterate to all features
for feature in layer.getFeatures():
context.setFeature(feature)
result = sum_expression.evaluate(context)
feature[output_idx] = result
layer.updateFeature(feature)
layer.commitChanges()
def sum_fields(layer, output_field_key, input_fields):
"""Sum the value of input_fields and put it as output_field.
:param layer: The vector layer.
:type layer: QgsVectorLayer
:param output_field_key: The output field definition key.
:type output_field_key: basestring
:param input_fields: List of input fields' name.
:type input_fields: list
"""
field_definition = definition(output_field_key)
output_field_name = field_definition['field_name']
# If the fields only has one element
if len(input_fields) == 1:
# Name is different, copy it
if input_fields[0] != output_field_name:
to_rename = {input_fields[0]: output_field_name}
# We copy only, it will be deleted later.
# We can't rename the field, we need to copy it as the same
# field might be used many times in the FMT tool.
copy_fields(layer, to_rename)
else:
# Name is same, do nothing
return
else:
# Creating expression
# Put field name in a double quote. See #4248
input_fields = ['"%s"' % f for f in input_fields]
string_expression = ' + '.join(input_fields)
sum_expression = QgsExpression(string_expression)
context = QgsExpressionContext()
context.setFields(layer.fields())
sum_expression.prepare(context)
# Get the output field index
output_idx = layer.fields().lookupField(output_field_name)
# Output index is not found
layer.startEditing()
if output_idx == -1:
output_field = create_field_from_definition(field_definition)
layer.addAttribute(output_field)
output_idx = layer.fields().lookupField(output_field_name)
# Iterate to all features
for feature in layer.getFeatures():
context.setFeature(feature)
result = sum_expression.evaluate(context)
feature[output_idx] = result
layer.updateFeature(feature)
layer.commitChanges()
def sum_fields(layer, output_field_key, input_fields):
"""Sum the value of input_fields and put it as output_field.
:param layer: The vector layer.
:type layer: QgsVectorLayer
:param output_field_key: The output field definition key.
:type output_field_key: basestring
:param input_fields: List of input fields' name.
:type input_fields: list
"""
field_definition = definition(output_field_key)
output_field_name = field_definition['field_name']
# If the fields only has one element
if len(input_fields) == 1:
# Name is different, copy it
if input_fields[0] != output_field_name:
copy_fields(layer, {
input_fields[0]: output_field_name})
# Name is same, do nothing
else:
return
else:
# Creating expression
# Put field name in a double quote. See #4248
input_fields = ['"%s"' % f for f in input_fields]
string_expression = ' + '.join(input_fields)
sum_expression = QgsExpression(string_expression)
context = QgsExpressionContext()
context.setFields(layer.pendingFields())
sum_expression.prepare(context)
# Get the output field index
output_idx = layer.fieldNameIndex(output_field_name)
# Output index is not found
if output_idx == -1:
output_field = create_field_from_definition(field_definition)
layer.startEditing()
layer.addAttribute(output_field)
layer.commitChanges()
output_idx = layer.fieldNameIndex(output_field_name)
layer.startEditing()
# Iterate to all features
for feature in layer.getFeatures():
context.setFeature(feature)
result = sum_expression.evaluate(context)
feature[output_idx] = result
layer.updateFeature(feature)
layer.commitChanges()
def zonal_stats(raster, vector):
"""Reclassify a continuous raster layer.
Issue https://github.com/inasafe/inasafe/issues/3190
The algorithm will take care about projections.
We don't want to reproject the raster layer.
So if CRS are different, we reproject the vector layer and then we do a
lookup from the reprojected layer to the original vector layer.
:param raster: The raster layer.
:type raster: QgsRasterLayer
:param vector: The vector layer.
:type vector: QgsVectorLayer
:return: The output of the zonal stats.
:rtype: QgsVectorLayer
.. versionadded:: 4.0
"""
output_layer_name = zonal_stats_steps['output_layer_name']
exposure = raster.keywords['exposure']
if raster.crs().authid() != vector.crs().authid():
layer = reproject(vector, raster.crs())
# We prepare the copy
output_layer = create_memory_layer(
output_layer_name,
vector.geometryType(),
vector.crs(),
vector.fields()
)
copy_layer(vector, output_layer)
else:
layer = create_memory_layer(
output_layer_name,
vector.geometryType(),
vector.crs(),
vector.fields()
)
copy_layer(vector, layer)
input_band = layer.keywords.get('active_band', 1)
analysis = QgsZonalStatistics(
layer,
raster,
'exposure_',
input_band,
QgsZonalStatistics.Sum)
result = analysis.calculateStatistics(None)
LOGGER.debug(tr('Zonal stats on %s : %s' % (raster.source(), result)))
output_field = exposure_count_field['field_name'] % exposure
if raster.crs().authid() != vector.crs().authid():
output_layer.startEditing()
field = create_field_from_definition(
exposure_count_field, exposure)
output_layer.addAttribute(field)
new_index = output_layer.fields().lookupField(field.name())
old_index = layer.fields().lookupField('exposure_sum')
for feature_input, feature_output in zip(
layer.getFeatures(), output_layer.getFeatures()):
output_layer.changeAttributeValue(
feature_input.id(), new_index, feature_input[old_index])
output_layer.commitChanges()
layer = output_layer
else:
fields_to_rename = {
'exposure_sum': output_field
}
if qgis_version() >= 21600:
rename_fields(layer, fields_to_rename)
else:
copy_fields(layer, fields_to_rename)
remove_fields(layer, list(fields_to_rename.keys()))
layer.commitChanges()
# The zonal stats is producing some None values. We need to fill these
# with 0. See issue : #3778
# We should start a new editing session as previous fields need to be
# committed first.
layer.startEditing()
request = QgsFeatureRequest()
expression = '\"%s\" is None' % output_field
request.setFilterExpression(expression)
request.setFlags(QgsFeatureRequest.NoGeometry)
index = layer.fields().lookupField(output_field)
for feature in layer.getFeatures():
if feature[output_field] is None:
layer.changeAttributeValue(feature.id(), index, 0)
layer.commitChanges()
layer.keywords = raster.keywords.copy()
layer.keywords['inasafe_fields'] = vector.keywords['inasafe_fields'].copy()
layer.keywords['inasafe_default_values'] = (
raster.keywords['inasafe_default_values'].copy())
key = exposure_count_field['key'] % raster.keywords['exposure']
# Special case here, one field is the exposure count and the total.
layer.keywords['inasafe_fields'][key] = output_field
layer.keywords['inasafe_fields'][total_field['key']] = output_field
layer.keywords['exposure_keywords'] = raster.keywords.copy()
layer.keywords['hazard_keywords'] = vector.keywords[
'hazard_keywords'].copy()
layer.keywords['aggregation_keywords'] = (
vector.keywords['aggregation_keywords'])
layer.keywords['layer_purpose'] = (
layer_purpose_aggregate_hazard_impacted['key'])
layer.keywords['title'] = output_layer_name
check_layer(layer)
return layer
def rename_remove_inasafe_fields(layer):
"""Loop over fields and rename fields which are used in InaSAFE.
:param layer: The layer
:type layer: QgsVectorLayer
"""
# Exposure
if layer.keywords['layer_purpose'] == layer_purpose_exposure['key']:
fields = get_fields(
layer.keywords['layer_purpose'], layer.keywords['exposure'])
# Hazard
elif layer.keywords['layer_purpose'] == layer_purpose_hazard['key']:
fields = get_fields(
layer.keywords['layer_purpose'], layer.keywords['hazard'])
# Aggregation
elif layer.keywords['layer_purpose'] == layer_purpose_aggregation['key']:
fields = get_fields(
layer.keywords['layer_purpose'])
# Add displaced_field definition to expected_fields
# for minimum needs calculator.
# If there is no displaced_field keyword, then pass
try:
if layer.keywords['inasafe_fields'][displaced_field['key']]:
fields.append(displaced_field)
except KeyError:
pass
expected_fields = {field['key']: field['field_name'] for field in fields}
# Rename fields
to_rename = {}
new_keywords = {}
for key, val in layer.keywords.get('inasafe_fields').iteritems():
if key in expected_fields:
if expected_fields[key] != val:
to_rename[val] = expected_fields[key]
new_keywords[key] = expected_fields[key]
copy_fields(layer, to_rename)
to_remove = to_rename.keys()
LOGGER.debug(
'Fields which have been renamed from %s :' % (
layer.keywords['layer_purpose']))
for old_name, new_name in to_rename.iteritems():
LOGGER.debug('%s -> %s' % (old_name, new_name))
# Houra, InaSAFE keywords match our concepts !
layer.keywords['inasafe_fields'].update(new_keywords)
# Remove unnecessary fields
for field in layer.fields().toList():
if field.name() not in expected_fields.values():
if field.name() not in to_remove:
to_remove.append(field.name())
remove_fields(layer, to_remove)
LOGGER.debug(
'Fields which have been removed from %s : %s'
% (layer.keywords['layer_purpose'], ' '.join(to_remove)))
def zonal_stats(raster, vector):
"""Reclassify a continuous raster layer.
Issue https://github.com/inasafe/inasafe/issues/3190
The algorithm will take care about projections.
We don't want to reproject the raster layer.
So if CRS are different, we reproject the vector layer and then we do a
lookup from the reprojected layer to the original vector layer.
:param raster: The raster layer.
:type raster: QgsRasterLayer
:param vector: The vector layer.
:type vector: QgsVectorLayer
:return: The output of the zonal stats.
:rtype: QgsVectorLayer
.. versionadded:: 4.0
"""
output_layer_name = zonal_stats_steps['output_layer_name']
exposure = raster.keywords['exposure']
if raster.crs().authid() != vector.crs().authid():
layer = reproject(vector, raster.crs())
# We prepare the copy
output_layer = create_memory_layer(
output_layer_name,
vector.geometryType(),
vector.crs(),
vector.fields()
)
copy_layer(vector, output_layer)
else:
layer = create_memory_layer(
output_layer_name,
vector.geometryType(),
vector.crs(),
vector.fields()
)
copy_layer(vector, layer)
input_band = layer.keywords.get('active_band', 1)
analysis = QgsZonalStatistics(
layer,
raster,
'exposure_',
input_band,
QgsZonalStatistics.Sum)
result = analysis.calculateStatistics(None)
LOGGER.debug(tr('Zonal stats on %s : %s' % (raster.source(), result)))
output_field = exposure_count_field['field_name'] % exposure
if raster.crs().authid() != vector.crs().authid():
output_layer.startEditing()
field = create_field_from_definition(
exposure_count_field, exposure)
output_layer.addAttribute(field)
new_index = output_layer.fields().lookupField(field.name())
old_index = layer.fields().lookupField('exposure_sum')
for feature_input, feature_output in zip(
layer.getFeatures(), output_layer.getFeatures()):
output_layer.changeAttributeValue(
feature_input.id(), new_index, feature_input[old_index])
output_layer.commitChanges()
layer = output_layer
else:
fields_to_rename = {
'exposure_sum': output_field
}
if qgis_version() >= 21600:
rename_fields(layer, fields_to_rename)
else:
copy_fields(layer, fields_to_rename)
remove_fields(layer, list(fields_to_rename.keys()))
layer.commitChanges()
# The zonal stats is producing some None values. We need to fill these
# with 0. See issue : #3778
# We should start a new editing session as previous fields need to be
# committed first.
layer.startEditing()
request = QgsFeatureRequest()
expression = '\"%s\" is None' % output_field
request.setFilterExpression(expression)
request.setFlags(QgsFeatureRequest.NoGeometry)
index = layer.fields().lookupField(output_field)
for feature in layer.getFeatures():
if feature[output_field] is None:
layer.changeAttributeValue(feature.id(), index, 0)
layer.commitChanges()
layer.keywords = raster.keywords.copy()
layer.keywords['inasafe_fields'] = vector.keywords['inasafe_fields'].copy()
layer.keywords['inasafe_default_values'] = (
raster.keywords['inasafe_default_values'].copy())
key = exposure_count_field['key'] % raster.keywords['exposure']
# Special case here, one field is the exposure count and the total.
layer.keywords['inasafe_fields'][key] = output_field
layer.keywords['inasafe_fields'][total_field['key']] = output_field
layer.keywords['exposure_keywords'] = raster.keywords.copy()
layer.keywords['hazard_keywords'] = vector.keywords[
'hazard_keywords'].copy()
layer.keywords['aggregation_keywords'] = (
vector.keywords['aggregation_keywords'])
layer.keywords['layer_purpose'] = (
layer_purpose_aggregate_hazard_impacted['key'])
layer.keywords['title'] = output_layer_name
check_layer(layer)
return layer
