示例#1
0
def clean_inasafe_fields(layer):
    """Clean inasafe_fields based on keywords.

    1. Must use standard field names.
    2. Sum up list of fields' value and put in the standard field name.
    3. Remove un-used fields.

    :param layer: The layer
    :type layer: QgsVectorLayer
    """
    fields = []
    # 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}

    # Convert the field name and sum up if needed
    new_keywords = {}
    for key, val in layer.keywords.get('inasafe_fields').iteritems():
        if key in expected_fields:
            if isinstance(val, basestring):
                val = [val]
            sum_fields(layer, key, val)
            new_keywords[key] = expected_fields[key]

    # Houra, InaSAFE keywords match our concepts !
    layer.keywords['inasafe_fields'].update(new_keywords)

    to_remove = []
    # Remove unnecessary fields (the one that is not in the inasafe_fields)
    for field in layer.fields().toList():
        if field.name() not in layer.keywords['inasafe_fields'].values():
            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)))
示例#2
0
def update_value_map(layer, exposure_key=None):
    """Assign inasafe values according to definitions for a vector layer.

    :param layer: The vector layer.
    :type layer: QgsVectorLayer

    :param exposure_key: The exposure key.
    :type exposure_key: str

    :return: The classified vector layer.
    :rtype: QgsVectorLayer

    .. versionadded:: 4.0
    """
    output_layer_name = assign_inasafe_values_steps['output_layer_name']
    output_layer_name = output_layer_name % layer.keywords['layer_purpose']

    keywords = layer.keywords
    inasafe_fields = keywords['inasafe_fields']

    classification = None
    if keywords['layer_purpose'] == layer_purpose_hazard['key']:
        if not inasafe_fields.get(hazard_value_field['key']):
            raise InvalidKeywordsForProcessingAlgorithm
        old_field = hazard_value_field
        new_field = hazard_class_field
        classification = active_classification(layer.keywords, exposure_key)

    elif keywords['layer_purpose'] == layer_purpose_exposure['key']:
        if not inasafe_fields.get(exposure_type_field['key']):
            raise InvalidKeywordsForProcessingAlgorithm
        old_field = exposure_type_field
        new_field = exposure_class_field
    else:
        raise InvalidKeywordsForProcessingAlgorithm

    # It's a hazard layer
    if exposure_key:
        if not active_thresholds_value_maps(keywords, exposure_key):
            raise InvalidKeywordsForProcessingAlgorithm
        value_map = active_thresholds_value_maps(keywords, exposure_key)
    # It's exposure layer
    else:
        if not keywords.get('value_map'):
            raise InvalidKeywordsForProcessingAlgorithm
        value_map = keywords.get('value_map')

    unclassified_column = inasafe_fields[old_field['key']]
    unclassified_index = layer.fields().lookupField(unclassified_column)

    reversed_value_map = {}
    for inasafe_class, values in list(value_map.items()):
        for val in values:
            reversed_value_map[val] = inasafe_class

    classified_field = QgsField()
    classified_field.setType(new_field['type'])
    classified_field.setName(new_field['field_name'])
    classified_field.setLength(new_field['length'])
    classified_field.setPrecision(new_field['precision'])

    layer.startEditing()
    layer.addAttribute(classified_field)

    classified_field_index = layer.fields(). \
        lookupField(classified_field.name())

    for feature in layer.getFeatures():
        attributes = feature.attributes()
        source_value = attributes[unclassified_index]
        classified_value = reversed_value_map.get(source_value)

        if not classified_value:
            classified_value = ''

        layer.changeAttributeValue(feature.id(), classified_field_index,
                                   classified_value)

    layer.commitChanges()

    remove_fields(layer, [unclassified_column])

    # We transfer keywords to the output.
    # We add new class field
    inasafe_fields[new_field['key']] = new_field['field_name']

    # and we remove hazard value field
    inasafe_fields.pop(old_field['key'])

    layer.keywords = keywords
    layer.keywords['inasafe_fields'] = inasafe_fields
    if exposure_key:
        value_map_key = 'value_maps'
    else:
        value_map_key = 'value_map'
    if value_map_key in list(layer.keywords.keys()):
        layer.keywords.pop(value_map_key)
    layer.keywords['title'] = output_layer_name
    if classification:
        layer.keywords['classification'] = classification

    check_layer(layer)
    return layer
示例#3
0
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)))
示例#5
0
def update_value_map(layer, exposure_key=None, callback=None):
    """Assign inasafe values according to definitions for a vector layer.

    :param layer: The vector layer.
    :type layer: QgsVectorLayer

    :param exposure_key: The exposure key.
    :type exposure_key: str

    :param callback: A function to all to indicate progress. The function
        should accept params 'current' (int), 'maximum' (int) and 'step' (str).
        Defaults to None.
    :type callback: function

    :return: The classified vector layer.
    :rtype: QgsVectorLayer

    .. versionadded:: 4.0
    """
    output_layer_name = assign_inasafe_values_steps['output_layer_name']
    processing_step = assign_inasafe_values_steps['step_name']
    output_layer_name = output_layer_name % layer.keywords['layer_purpose']

    keywords = layer.keywords
    inasafe_fields = keywords['inasafe_fields']

    classification = None
    if keywords['layer_purpose'] == layer_purpose_hazard['key']:
        if not inasafe_fields.get(hazard_value_field['key']):
            raise InvalidKeywordsForProcessingAlgorithm
        old_field = hazard_value_field
        new_field = hazard_class_field
        classification = active_classification(layer.keywords, exposure_key)

    elif keywords['layer_purpose'] == layer_purpose_exposure['key']:
        if not inasafe_fields.get(exposure_type_field['key']):
            raise InvalidKeywordsForProcessingAlgorithm
        old_field = exposure_type_field
        new_field = exposure_class_field
    else:
        raise InvalidKeywordsForProcessingAlgorithm

    # It's a hazard layer
    if exposure_key:
        if not active_thresholds_value_maps(keywords, exposure_key):
            raise InvalidKeywordsForProcessingAlgorithm
        value_map = active_thresholds_value_maps(keywords, exposure_key)
    # It's exposure layer
    else:
        if not keywords.get('value_map'):
            raise InvalidKeywordsForProcessingAlgorithm
        value_map = keywords.get('value_map')

    unclassified_column = inasafe_fields[old_field['key']]
    unclassified_index = layer.fieldNameIndex(unclassified_column)

    reversed_value_map = {}
    for inasafe_class, values in value_map.iteritems():
        for val in values:
            reversed_value_map[val] = inasafe_class

    classified_field = QgsField()
    classified_field.setType(new_field['type'])
    classified_field.setName(new_field['field_name'])
    classified_field.setLength(new_field['length'])
    classified_field.setPrecision(new_field['precision'])

    layer.startEditing()
    layer.addAttribute(classified_field)

    classified_field_index = layer.fieldNameIndex(classified_field.name())

    for feature in layer.getFeatures():
        attributes = feature.attributes()
        source_value = attributes[unclassified_index]
        classified_value = reversed_value_map.get(source_value)

        if not classified_value:
            classified_value = ''

        layer.changeAttributeValue(
            feature.id(), classified_field_index, classified_value)

    layer.commitChanges()

    remove_fields(layer, [unclassified_column])

    # We transfer keywords to the output.
    # We add new class field
    inasafe_fields[new_field['key']] = new_field['field_name']

    # and we remove hazard value field
    inasafe_fields.pop(old_field['key'])

    layer.keywords = keywords
    layer.keywords['inasafe_fields'] = inasafe_fields
    if exposure_key:
        value_map_key = 'value_maps'
    else:
        value_map_key = 'value_map'
    if value_map_key in layer.keywords.keys():
        layer.keywords.pop(value_map_key)
    layer.keywords['title'] = output_layer_name
    if classification:
        layer.keywords['classification'] = classification

    check_layer(layer)
    return layer
示例#6
0
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