def requires_clipping(self):
"""Check to clip or not to clip layers.
If self._function is a 'new-style' impact function, then
return False -- clipping is unnecessary, else return True
:returns: To clip or not to clip.
:rtype: bool
:raises: InsufficientParametersError if function parameter is not set.
InvalidParameterError if the function has unknown style.
"""
f = self.function()
if f is None:
message = self.tr('Error: Function is not provided.')
raise InsufficientParametersError(message)
style = getSafeImpactFunctionType(f)
if style == 'old-style':
return True
elif style == 'qgis2.0':
return False
else:
message = self.tr('Error: Function has unknown style.')
raise InvalidParameterError(message)
def _get_layer(self, layer):
"""Analyze style of self._function and return appropriate
class of the layer.
:param layer: A layer.
:type layer: QgsMapLayer or SAFE layer.
:returns: The layer of appropriate type
:rtype: SAFE or QgisWrapper
:raises: InsufficientParametersError if self._function is not set,
InvalidParameterError if style of self._function is not
in ('old-style', 'qgis2.0')
Any exceptions raised by other libraries will be propogated.
"""
if self._function is None or self._function == '':
message = self.tr('Error: Function not set.')
raise InsufficientParametersError(message)
# Get type of the impact function (old-style or new-style)
try:
func_type = getSafeImpactFunctionType(self._function)
if func_type == 'old-style':
return convertToSafeLayer(layer)
elif func_type == 'qgis2.0':
# convert for new style impact function
return QgisWrapper(layer)
else:
message = self.tr('Error: Function has unknown style.')
raise InvalidParameterError(message)
except:
raise
def readKeywordsFromLayer(theLayer, keyword):
"""Get metadata from the keywords file associated with a layer.
.. note:: Requires a inasafe layer instance as parameter.
.. seealso:: getKeywordFromPath
Args:
* theLayer - a InaSAFE layer (vector or raster)
* keyword - the metadata keyword to retrieve e.g. 'title'
Returns:
A string containing the retrieved value for the keyword.
Raises:
KeywordNotFoundError if the keyword is not recognised.
"""
value = None
if theLayer is None:
raise InvalidParameterError()
try:
value = theLayer.get_keywords(keyword)
except Exception, e:
message = \
tr('Keyword retrieval failed for %s (%s) \n %s' % (
theLayer.get_filename(), keyword, str(e)))
raise KeywordNotFoundError(message)
def getStyleInfo(theLayer):
"""Get styleinfo associated with a layer.
Args:
* theLayer - InaSAFE layer (raster or vector)
Returns:
A list of dictionaries containing styleinfo info for a layer.
Raises:
* StyleInfoNotFoundError if the style is not found.
* InvalidParameterError if the paramers are not correct.
"""
if not theLayer:
raise InvalidParameterError()
if not hasattr(theLayer, 'get_style_info'):
message = \
tr('Argument "%s" was not a valid layer instance' %
theLayer)
raise StyleInfoNotFoundError(message)
try:
value = theLayer.get_style_info()
except Exception, e:
message = \
tr('Styleinfo retrieval failed for %s\n %s' % (
theLayer.get_filename(), str(e)))
raise StyleInfoNotFoundError(message)
def readKeywordsFromFile(theLayerPath, theKeyword=None):
"""Get metadata from the keywords file associated with a local
file in the file system.
.. note:: Requires a str representing a file path instance
as parameter As opposed to readKeywordsFromLayer which
takes a inasafe file object as parameter.
.. seealso:: readKeywordsFromLayer
Args:
* theLayerPath - a string representing a path to a layer
(e.g. '/tmp/foo.shp', '/tmp/foo.tif')
* theKeyword - optional - the metadata keyword to retrieve e.g. 'title'
Returns:
A string containing the retrieved value for the keyword if
the keyword argument is specified, otherwise the
complete keywords dictionary is returned.
Raises:
KeywordNotFoundError if the keyword is not recognised.
"""
# check the source layer path is valid
if not os.path.isfile(theLayerPath):
myMessage = tr('Cannot get keywords from a non-existent file.'
'%s does not exist.' % theLayerPath)
raise InvalidParameterError(myMessage)
# check there really is a keywords file for this layer
myKeywordFilePath = os.path.splitext(theLayerPath)[0]
myKeywordFilePath += '.keywords'
if not os.path.isfile(myKeywordFilePath):
myMessage = tr('No keywords file found for %s' % myKeywordFilePath)
raise InvalidParameterError(myMessage)
# now get the requested keyword using the inasafe library
myDictionary = None
try:
myDictionary = read_keywords(myKeywordFilePath)
except Exception, e:
myMessage = \
tr('Keyword retrieval failed for %s (%s) \n %s' % (
myKeywordFilePath, theKeyword, str(e)))
raise KeywordNotFoundError(myMessage)
def read_file_keywords(layer_path, keyword=None):
"""Get metadata from the keywords file associated with a local
file in the file system.
.. note:: Requires a str representing a file path instance
as parameter As opposed to readKeywordsFromLayer which
takes a inasafe file object as parameter.
.. seealso:: readKeywordsFromLayer
:param: layer_path: a string representing a path to a layer
(e.g. '/tmp/foo.shp', '/tmp/foo.tif')
:type layer_path: str
:param keyword: optional - the metadata keyword to retrieve e.g. 'title'
:type keyword: str
:return: A string containing the retrieved value for the keyword if
the keyword argument is specified, otherwise the
complete keywords dictionary is returned.
:raises: KeywordNotFoundError, NoKeywordsFoundError, InvalidParameterError
Note:
* KeywordNotFoundError - occurs when the keyword is not recognised.
* NoKeywordsFoundError - occurs when no keyword file exists.
* InvalidParameterError - occurs when the layer does not exist.
"""
# check the source layer path is valid
if not os.path.isfile(layer_path):
message = tr('Cannot get keywords from a non-existent file.'
'%s does not exist.' % layer_path)
raise InvalidParameterError(message)
# check there really is a keywords file for this layer
keyword_file_path = os.path.splitext(layer_path)[0]
keyword_file_path += '.keywords'
if not os.path.isfile(keyword_file_path):
message = tr('No keywords file found for %s' % keyword_file_path)
raise NoKeywordsFoundError(message)
# now get the requested keyword using the inasafe library
dictionary = None
try:
dictionary = read_keywords(keyword_file_path)
except Exception, e:
message = \
tr('Keyword retrieval failed for %s (%s) \n %s' % (
keyword_file_path, keyword, str(e)))
raise KeywordNotFoundError(message)
def calculate_zonal_stats(raster_layer, polygon_layer):
"""Calculate zonal statics given two layers.
:param raster_layer: A QGIS raster layer.
:type raster_layer: QgsRasterLayer
:param polygon_layer: A QGIS vector layer containing polygons.
:type polygon_layer: QgsVectorLayer, QgsMapLayer
:returns: A data structure containing sum, mean, min, max,
count of raster values for each polygonal area.
:rtype: dict
:raises: InvalidParameterError, InvalidGeometryError
Note:
* InvalidParameterError if incorrect inputs are received.
* InvalidGeometryError if none geometry is found during calculations.
* Any other exceptions are propagated.
Example of output data structure:
{ 1: {'sum': 10, 'count': 20, 'min': 1, 'max': 4, 'mean': 2},
2: {'sum': 10, 'count': 20, 'min': 1, 'max': 4, 'mean': 2},
3 {'sum': 10, 'count': 20, 'min': 1, 'max': 4, 'mean': 2}}
The key in the outer dict is the feature id
.. note:: This is a python port of the zonal stats implementation in QGIS
. See https://github.com/qgis/Quantum-GIS/blob/master/src/analysis/
vector/qgszonalstatistics.cpp
.. note:: Currently not projection checks are made to ensure that both
layers are in the same CRS - we assume they are.
"""
if not is_polygon_layer(polygon_layer):
raise InvalidParameterError(
tr('Zonal stats needs a polygon layer in order to compute '
'statistics.'))
if not is_raster_layer(raster_layer):
raise InvalidParameterError(
tr('Zonal stats needs a raster layer in order to compute statistics.'
))
LOGGER.debug('Calculating zonal stats for:')
LOGGER.debug('Raster: %s' % raster_layer.source())
LOGGER.debug('Vector: %s' % polygon_layer.source())
myResults = {}
myRasterSource = raster_layer.source()
myFid = gdal.Open(str(myRasterSource), gdal.GA_ReadOnly)
myGeoTransform = myFid.GetGeoTransform()
myColumns = myFid.RasterXSize
myRows = myFid.RasterYSize
# Get first band.
myBand = myFid.GetRasterBand(1)
myNoData = myBand.GetNoDataValue()
#print 'No data %s' % myNoData
myCellSizeX = myGeoTransform[1]
if myCellSizeX < 0:
myCellSizeX = -myCellSizeX
myCellSizeY = myGeoTransform[5]
if myCellSizeY < 0:
myCellSizeY = -myCellSizeY
myRasterBox = QgsRectangle(myGeoTransform[0],
myGeoTransform[3] - (myCellSizeY * myRows),
myGeoTransform[0] + (myCellSizeX * myColumns),
myGeoTransform[3])
rasterGeom = QgsGeometry.fromRect(myRasterBox)
# Get vector layer
myProvider = polygon_layer.dataProvider()
if myProvider is None:
myMessage = tr('Could not obtain data provider from layer "%s"') % (
polygon_layer.source())
raise Exception(myMessage)
myRequest = QgsFeatureRequest()
crs = osr.SpatialReference()
crs.ImportFromProj4(str(polygon_layer.crs().toProj4()))
myCount = 0
for myFeature in myProvider.getFeatures(myRequest):
myGeometry = myFeature.geometry()
if myGeometry is None:
myMessage = tr('Feature %d has no geometry or geometry is invalid'
) % (myFeature.id())
raise InvalidGeometryError(myMessage)
myCount += 1
myFeatureBox = myGeometry.boundingBox().intersect(myRasterBox)
print 'NEW AGGR: %s' % myFeature.id()
#print 'Raster Box: %s' % myRasterBox.asWktCoordinates()
#print 'Feature Box: %s' % myFeatureBox.asWktCoordinates()
myOffsetX, myOffsetY, myCellsX, myCellsY = intersection_box(
myRasterBox, myFeatureBox, myCellSizeX, myCellSizeY)
# If the poly does not intersect the raster just continue
if None in [myOffsetX, myOffsetY, myCellsX, myCellsY]:
continue
# avoid access to cells outside of the raster (may occur because of
# rounding)
if (myOffsetX + myCellsX) > myColumns:
myOffsetX = myColumns - myOffsetX
if (myOffsetY + myCellsY) > myRows:
myCellsY = myRows - myOffsetY
myIntersectedGeom = rasterGeom.intersection(myGeometry)
mySum, myCount = numpy_stats(myBand, myIntersectedGeom, myGeoTransform,
myNoData, crs)
if myCount <= 1:
# The cell resolution is probably larger than the polygon area.
# We switch to precise pixel - polygon intersection in this case
mySum, myCount = precise_stats(myBand, myGeometry, myOffsetX,
myOffsetY, myCellsX, myCellsY,
myCellSizeX, myCellSizeY,
myRasterBox, myNoData)
#print mySum, myCount
if myCount == 0:
myMean = 0
else:
myMean = mySum / myCount
myResults[myFeature.id()] = {
'sum': mySum,
'count': myCount,
'mean': myMean
}
# noinspection PyUnusedLocal
myFid = None # Close
return myResults
def _clipRasterLayer(theLayer,
theExtent,
theCellSize=None,
theExtraKeywords=None):
"""Clip a Hazard or Exposure raster layer to the extents provided. The
layer must be a raster layer or an exception will be thrown.
.. note:: The extent *must* be in EPSG:4326.
The output layer will always be in WGS84/Geographic.
Args:
* theLayer - a valid QGIS raster layer in EPSG:4326
* theExtent either: an array representing the exposure layer
extents in the form [xmin, ymin, xmax, ymax]. It is assumed
that the coordinates are in EPSG:4326 although currently
no checks are made to enforce this.
or: A QgsGeometry of type polygon. **Polygon clipping is
currently only supported for vector datasets.**
* theCellSize - cell size (in GeoCRS) which the layer should
be resampled to. If not provided for a raster layer (i.e.
theCellSize=None), the native raster cell size will be used.
Returns:
Path to the output clipped layer (placed in the
system temp dir).
Raises:
Exception if input layer is a density layer in projected coordinates -
see issue #123
"""
if not theLayer or not theExtent:
myMessage = tr('Layer or Extent passed to clip is None.')
raise InvalidParameterError(myMessage)
if theLayer.type() != QgsMapLayer.RasterLayer:
myMessage = tr('Expected a raster layer but received a %s.' %
str(theLayer.type()))
raise InvalidParameterError(myMessage)
myWorkingLayer = str(theLayer.source())
# Check for existence of keywords file
myKeywordsPath = myWorkingLayer[:-4] + '.keywords'
myMessage = tr('Input file to be clipped "%s" does not have the '
'expected keywords file %s' %
(myWorkingLayer, myKeywordsPath))
verify(os.path.isfile(myKeywordsPath), myMessage)
# Raise exception if layer is projected and refers to density (issue #123)
# FIXME (Ole): Need to deal with it - e.g. by automatically reprojecting
# the layer at this point and setting the native resolution accordingly
# in its keywords.
myKeywords = readKeywordsFromFile(myKeywordsPath)
if 'datatype' in myKeywords and myKeywords['datatype'] == 'density':
if str(theLayer.crs().authid()) != 'EPSG:4326':
# This layer is not WGS84 geographic
myMessage = ('Layer %s represents density but has spatial '
'reference "%s". Density layers must be given in '
'WGS84 geographic coordinates, so please reproject '
'and try again. For more information, see issue '
'https://github.com/AIFDR/inasafe/issues/123' %
(myWorkingLayer, theLayer.crs().toProj4()))
raise InvalidProjectionError(myMessage)
# We need to provide gdalwarp with a dataset for the clip
# because unline gdal_translate, it does not take projwin.
myClipKml = extentToKml(theExtent)
# Create a filename for the clipped, resampled and reprojected layer
myHandle, myFilename = tempfile.mkstemp('.tif', 'clip_', temp_dir())
os.close(myHandle)
os.remove(myFilename)
# If no cell size is specified, we need to run gdalwarp without
# specifying the output pixel size to ensure the raster dims
# remain consistent.
myBinaryList = which('gdalwarp')
LOGGER.debug('Path for gdalwarp: %s' % myBinaryList)
if len(myBinaryList) < 1:
raise CallGDALError(tr('gdalwarp could not be found on your computer'))
# Use the first matching gdalwarp found
myBinary = myBinaryList[0]
if theCellSize is None:
myCommand = ('%s -q -t_srs EPSG:4326 -r near '
'-cutline %s -crop_to_cutline -of GTiff '
'"%s" "%s"' %
(myBinary, myClipKml, myWorkingLayer, myFilename))
else:
myCommand = ('%s -q -t_srs EPSG:4326 -r near -tr %f %f '
'-cutline %s -crop_to_cutline -of GTiff '
'"%s" "%s"' % (myBinary, theCellSize, theCellSize,
myClipKml, myWorkingLayer, myFilename))
LOGGER.debug(myCommand)
myResult = QProcess().execute(myCommand)
# For QProcess exit codes see
# http://qt-project.org/doc/qt-4.8/qprocess.html#execute
if myResult == -2: # cannot be started
myMessageDetail = tr('Process could not be started.')
myMessage = tr('<p>Error while executing the following shell command:'
'</p><pre>%s</pre><p>Error message: %s' %
(myCommand, myMessageDetail))
raise CallGDALError(myMessage)
elif myResult == -1: # process crashed
myMessageDetail = tr('Process could not be started.')
myMessage = tr('<p>Error while executing the following shell command:'
'</p><pre>%s</pre><p>Error message: %s' %
(myCommand, myMessageDetail))
raise CallGDALError(myMessage)
# .. todo:: Check the result of the shell call is ok
myKeywordIO = KeywordIO()
myKeywordIO.copyKeywords(theLayer,
myFilename,
theExtraKeywords=theExtraKeywords)
return myFilename # Filename of created file
def _clipVectorLayer(theLayer,
theExtent,
theExtraKeywords=None,
theExplodeFlag=True,
theHardClipFlag=False):
"""Clip a Hazard or Exposure layer to the
extents of the current view frame. The layer must be a
vector layer or an exception will be thrown.
The output layer will always be in WGS84/Geographic.
Args:
* theLayer - a valid QGIS vector layer in EPSG:4326
* theExtent either: an array representing the exposure layer
extents in the form [xmin, ymin, xmax, ymax]. It is assumed
that the coordinates are in EPSG:4326 although currently
no checks are made to enforce this.
or: A QgsGeometry of type polygon. **Polygon clipping is
currently only supported for vector datasets.**
* theExtraKeywords - any additional keywords over and above the
original keywords that should be associated with the cliplayer.
* theExplodeFlag - a bool specifying whether multipart features
should be 'exploded' into singleparts.
* theHardClipFlag - a bool specifying whether line and polygon features
that extend beyond the extents should be clipped such that they
are reduced in size to the part of the geometry that intersects
the extent only. Default is False.
Returns:
Path to the output clipped layer (placed in the system temp dir).
Raises:
None
"""
if not theLayer or not theExtent:
myMessage = tr('Layer or Extent passed to clip is None.')
raise InvalidParameterError(myMessage)
if theLayer.type() != QgsMapLayer.VectorLayer:
myMessage = tr('Expected a vector layer but received a %s.' %
str(theLayer.type()))
raise InvalidParameterError(myMessage)
#myHandle, myFilename = tempfile.mkstemp('.sqlite', 'clip_',
# temp_dir())
myHandle, myFilename = tempfile.mkstemp('.shp', 'clip_', temp_dir())
# Ensure the file is deleted before we try to write to it
# fixes windows specific issue where you get a message like this
# ERROR 1: c:\temp\inasafe\clip_jpxjnt.shp is not a directory.
# This is because mkstemp creates the file handle and leaves
# the file open.
os.close(myHandle)
os.remove(myFilename)
# Get the clip extents in the layer's native CRS
myGeoCrs = QgsCoordinateReferenceSystem()
myGeoCrs.createFromId(4326, QgsCoordinateReferenceSystem.EpsgCrsId)
myXForm = QgsCoordinateTransform(myGeoCrs, theLayer.crs())
myAllowedClipTypes = [QGis.WKBPolygon, QGis.WKBPolygon25D]
if type(theExtent) is list:
myRect = QgsRectangle(theExtent[0], theExtent[1], theExtent[2],
theExtent[3])
# noinspection PyCallByClass
myClipPolygon = QgsGeometry.fromRect(myRect)
elif (type(theExtent) is QgsGeometry
and theExtent.wkbType in myAllowedClipTypes):
myRect = theExtent.boundingBox().toRectF()
myClipPolygon = theExtent
else:
raise InvalidClipGeometryError(
tr('Clip geometry must be an extent or a single part'
'polygon based geometry.'))
myProjectedExtent = myXForm.transformBoundingBox(myRect)
# Get vector layer
myProvider = theLayer.dataProvider()
if myProvider is None:
myMessage = tr('Could not obtain data provider from '
'layer "%s"' % theLayer.source())
raise Exception(myMessage)
# Get the layer field list, select by our extent then write to disk
# .. todo:: FIXME - for different geometry types we should implement
# different clipping behaviour e.g. reject polygons that
# intersect the edge of the bbox. Tim
myAttributes = myProvider.attributeIndexes()
myFetchGeometryFlag = True
myUseIntersectFlag = True
myProvider.select(myAttributes, myProjectedExtent, myFetchGeometryFlag,
myUseIntersectFlag)
myFieldList = myProvider.fields()
myWriter = QgsVectorFileWriter(
myFilename,
'UTF-8',
myFieldList,
theLayer.wkbType(),
myGeoCrs,
#'SQLite') # FIXME (Ole): This works but is far too slow
'ESRI Shapefile')
if myWriter.hasError() != QgsVectorFileWriter.NoError:
myMessage = tr('Error when creating shapefile: <br>Filename:'
'%s<br>Error: %s' % (myFilename, myWriter.hasError()))
raise Exception(myMessage)
# Reverse the coordinate xform now so that we can convert
# geometries from layer crs to geocrs.
myXForm = QgsCoordinateTransform(theLayer.crs(), myGeoCrs)
# Retrieve every feature with its geometry and attributes
myFeature = QgsFeature()
myCount = 0
while myProvider.nextFeature(myFeature):
myGeometry = myFeature.geometry()
# Loop through the parts adding them to the output file
# we write out single part features unless theExplodeFlag is False
if theExplodeFlag:
myGeometryList = explodeMultiPartGeometry(myGeometry)
else:
myGeometryList = [myGeometry]
for myPart in myGeometryList:
myPart.transform(myXForm)
if theHardClipFlag:
# Remove any dangling bits so only intersecting area is
# kept.
myPart = clipGeometry(myClipPolygon, myPart)
if myPart is None:
continue
myFeature.setGeometry(myPart)
myWriter.addFeature(myFeature)
myCount += 1
del myWriter # Flush to disk
if myCount < 1:
myMessage = tr('No features fall within the clip extents. '
'Try panning / zooming to an area containing data '
'and then try to run your analysis again.'
'If hazard and exposure data doesn\'t overlap '
'at all, it is not possible to do an analysis.'
'Another possibility is that the layers do overlap '
'but because they may have different spatial '
'references, they appear to be disjoint. '
'If this is the case, try to turn on reproject '
'on-the-fly in QGIS.')
raise NoFeaturesInExtentError(myMessage)
myKeywordIO = KeywordIO()
myKeywordIO.copyKeywords(theLayer,
myFilename,
theExtraKeywords=theExtraKeywords)
return myFilename # Filename of created file
def calculate_zonal_stats(raster_layer, polygon_layer):
"""Calculate zonal statics given two layers.
:param raster_layer: A QGIS raster layer.
:type raster_layer: QgsRasterLayer, QgsMapLayer
:param polygon_layer: A QGIS vector layer containing polygons.
:type polygon_layer: QgsVectorLayer, QgsMapLayer
:returns: A data structure containing sum, mean, min, max,
count of raster values for each polygonal area.
:rtype: dict
:raises: InvalidParameterError, InvalidGeometryError
Note:
* InvalidParameterError if incorrect inputs are received.
* InvalidGeometryError if none geometry is found during calculations.
* Any other exceptions are propagated.
Example of output data structure:
{ 1: {'sum': 10, 'count': 20, 'min': 1, 'max': 4, 'mean': 2},
2: {'sum': 10, 'count': 20, 'min': 1, 'max': 4, 'mean': 2},
3 {'sum': 10, 'count': 20, 'min': 1, 'max': 4, 'mean': 2}}
The key in the outer dict is the feature id
.. note:: This is a python port of the zonal stats implementation in QGIS
. See https://github.com/qgis/Quantum-GIS/blob/master/src/analysis/
vector/qgszonalstatistics.cpp
.. note:: Currently not projection checks are made to ensure that both
layers are in the same CRS - we assume they are.
"""
if not is_polygon_layer(polygon_layer):
raise InvalidParameterError(
tr('Zonal stats needs a polygon layer in order to compute '
'statistics.'))
if not is_raster_layer(raster_layer):
raise InvalidParameterError(
tr('Zonal stats needs a raster layer in order to compute statistics.'
))
LOGGER.debug('Calculating zonal stats for:')
LOGGER.debug('Raster: %s' % raster_layer.source())
LOGGER.debug('Vector: %s' % polygon_layer.source())
results = {}
raster_source = raster_layer.source()
feature_id = gdal.Open(str(raster_source), gdal.GA_ReadOnly)
geo_transform = feature_id.GetGeoTransform()
columns = feature_id.RasterXSize
rows = feature_id.RasterYSize
# Get first band.
band = feature_id.GetRasterBand(1)
no_data = band.GetNoDataValue()
#print 'No data %s' % no_data
cell_size_x = geo_transform[1]
if cell_size_x < 0:
cell_size_x = -cell_size_x
cell_size_y = geo_transform[5]
if cell_size_y < 0:
cell_size_y = -cell_size_y
raster_box = QgsRectangle(geo_transform[0],
geo_transform[3] - (cell_size_y * rows),
geo_transform[0] + (cell_size_x * columns),
geo_transform[3])
#noinspection PyCallByClass,PyTypeChecker,PyArgumentList
raster_geometry = QgsGeometry.fromRect(raster_box)
# Get vector layer
provider = polygon_layer.dataProvider()
if provider is None:
message = tr('Could not obtain data provider from layer "%s"') % (
polygon_layer.source())
raise Exception(message)
request = QgsFeatureRequest()
crs = osr.SpatialReference()
crs.ImportFromProj4(str(polygon_layer.crs().toProj4()))
count = 0
for myFeature in provider.getFeatures(request):
geometry = myFeature.geometry()
if geometry is None:
message = tr('Feature %d has no geometry or geometry is invalid'
) % (myFeature.id())
raise InvalidGeometryError(message)
count += 1
feature_box = geometry.boundingBox().intersect(raster_box)
print 'NEW AGGR: %s' % myFeature.id()
#print 'Raster Box: %s' % raster_box.asWktCoordinates()
#print 'Feature Box: %s' % feature_box.asWktCoordinates()
offset_x, offset_y, cells_x, cells_y = intersection_box(
raster_box, feature_box, cell_size_x, cell_size_y)
# If the poly does not intersect the raster just continue
if None in [offset_x, offset_y, cells_x, cells_y]:
continue
# avoid access to cells outside of the raster (may occur because of
# rounding)
if (offset_x + cells_x) > columns:
offset_x = columns - offset_x
if (offset_y + cells_y) > rows:
cells_y = rows - offset_y
intersected_geometry = raster_geometry.intersection(geometry)
geometry_sum, count = numpy_stats(band, intersected_geometry,
geo_transform, no_data, crs)
if count <= 1:
# The cell resolution is probably larger than the polygon area.
# We switch to precise pixel - polygon intersection in this case
geometry_sum, count = precise_stats(band, geometry, offset_x,
offset_y, cells_x, cells_y,
cell_size_x, cell_size_y,
raster_box, no_data)
#print geometry_sum, count
if count == 0:
mean = 0
else:
mean = geometry_sum / count
results[myFeature.id()] = {
'sum': geometry_sum,
'count': count,
'mean': mean
}
# noinspection PyUnusedLocal
feature_id = None # Close
return results
def _clip_vector_layer(
layer,
extent,
extra_keywords=None,
explode_flag=True,
hard_clip_flag=False,
explode_attribute=None):
"""Clip a Hazard or Exposure layer to the extents provided.
The layer must be a vector layer or an exception will be thrown.
The output layer will always be in WGS84/Geographic.
:param layer: A valid QGIS vector or raster layer
:type layer:
:param extent: Either an array representing the exposure layer extents
in the form [xmin, ymin, xmax, ymax]. It is assumed that the
coordinates are in EPSG:4326 although currently no checks are made to
enforce this.
or:
A QgsGeometry of type polygon.
**Polygon clipping is currently only supported for vector datasets.**
:type extent: list(float, float, float, float)
:param extra_keywords: Optional keywords dictionary to be added to
output layer.
:type extra_keywords: dict
:param explode_flag: A bool specifying whether multipart features
should be 'exploded' into singleparts.
**This parameter is ignored for raster layer clipping.**
:type explode_flag: bool
:param hard_clip_flag: A bool specifying whether line and polygon
features that extend beyond the extents should be clipped such that
they are reduced in size to the part of the geometry that intersects
the extent only. Default is False.
**This parameter is ignored for raster layer clipping.**
:type hard_clip_flag: bool
:param explode_attribute: A str specifying to which attribute #1,
#2 and so on will be added in case of explode_flag being true. The
attribute is modified only if there are at least 2 parts.
:type explode_attribute: str
:returns: Clipped layer (placed in the system temp dir). The output layer
will be reprojected to EPSG:4326 if needed.
:rtype: QgsVectorLayer
"""
if not layer or not extent:
myMessage = tr('Layer or Extent passed to clip is None.')
raise InvalidParameterError(myMessage)
if layer.type() != QgsMapLayer.VectorLayer:
myMessage = tr('Expected a vector layer but received a %s.' %
str(layer.type()))
raise InvalidParameterError(myMessage)
#myHandle, myFilename = tempfile.mkstemp('.sqlite', 'clip_',
# temp_dir())
myHandle, myFilename = tempfile.mkstemp('.shp', 'clip_',
temp_dir())
# Ensure the file is deleted before we try to write to it
# fixes windows specific issue where you get a message like this
# ERROR 1: c:\temp\inasafe\clip_jpxjnt.shp is not a directory.
# This is because mkstemp creates the file handle and leaves
# the file open.
os.close(myHandle)
os.remove(myFilename)
# Get the clip extents in the layer's native CRS
myGeoCrs = QgsCoordinateReferenceSystem()
myGeoCrs.createFromId(4326, QgsCoordinateReferenceSystem.EpsgCrsId)
myXForm = QgsCoordinateTransform(myGeoCrs, layer.crs())
myAllowedClipTypes = [QGis.WKBPolygon, QGis.WKBPolygon25D]
if type(extent) is list:
myRect = QgsRectangle(
extent[0], extent[1],
extent[2], extent[3])
# noinspection PyCallByClass
myClipPolygon = QgsGeometry.fromRect(myRect)
elif (type(extent) is QgsGeometry and
extent.wkbType in myAllowedClipTypes):
myRect = extent.boundingBox().toRectF()
myClipPolygon = extent
else:
raise InvalidClipGeometryError(
tr(
'Clip geometry must be an extent or a single part'
'polygon based geometry.'))
myProjectedExtent = myXForm.transformBoundingBox(myRect)
# Get vector layer
myProvider = layer.dataProvider()
if myProvider is None:
myMessage = tr('Could not obtain data provider from '
'layer "%s"' % layer.source())
raise Exception(myMessage)
# Get the layer field list, select by our extent then write to disk
# .. todo:: FIXME - for different geometry types we should implement
# different clipping behaviour e.g. reject polygons that
# intersect the edge of the bbox. Tim
myAttributes = myProvider.attributeIndexes()
myFetchGeometryFlag = True
myUseIntersectFlag = True
myProvider.select(
myAttributes,
myProjectedExtent,
myFetchGeometryFlag,
myUseIntersectFlag)
myFieldList = myProvider.fields()
myWriter = QgsVectorFileWriter(
myFilename,
'UTF-8',
myFieldList,
layer.wkbType(),
myGeoCrs,
#'SQLite') # FIXME (Ole): This works but is far too slow
'ESRI Shapefile')
if myWriter.hasError() != QgsVectorFileWriter.NoError:
myMessage = tr('Error when creating shapefile: <br>Filename:'
'%s<br>Error: %s' %
(myFilename, myWriter.hasError()))
raise Exception(myMessage)
# Reverse the coordinate xform now so that we can convert
# geometries from layer crs to geocrs.
myXForm = QgsCoordinateTransform(layer.crs(), myGeoCrs)
# Retrieve every feature with its geometry and attributes
myFeature = QgsFeature()
myCount = 0
myHasMultipart = False
if explode_attribute is not None:
theExplodeAttributeIndex = myProvider.fieldNameIndex(
explode_attribute)
while myProvider.nextFeature(myFeature):
myGeometry = myFeature.geometry()
if explode_attribute is not None:
myAttrs = myFeature.attributeMap()
# Loop through the parts adding them to the output file
# we write out single part features unless explode_flag is False
if explode_flag:
myGeometryList = explode_multipart_geometry(myGeometry)
else:
myGeometryList = [myGeometry]
for myPartIndex, myPart in enumerate(myGeometryList):
myPart.transform(myXForm)
if hard_clip_flag:
# Remove any dangling bits so only intersecting area is
# kept.
myPart = clip_geometry(myClipPolygon, myPart)
if myPart is None:
continue
myFeature.setGeometry(myPart)
# There are multiple parts and we want to show it in the
# explode_attribute
if myPartIndex > 0 and explode_attribute is not None:
myHasMultipart = True
myPartAttr = QVariant(
'%s #%s' % (myAttrs[theExplodeAttributeIndex].toString(),
myPartIndex))
myFeature.changeAttribute(theExplodeAttributeIndex, myPartAttr)
myWriter.addFeature(myFeature)
myCount += 1
del myWriter # Flush to disk
if myCount < 1:
myMessage = tr(
'No features fall within the clip extents. Try panning / zooming '
'to an area containing data and then try to run your analysis '
'again. If hazard and exposure data doesn\'t overlap at all, it '
'is not possible to do an analysis. Another possibility is that '
'the layers do overlap but because they may have different '
'spatial references, they appear to be disjointed. If this is the '
'case, try to turn on reproject on-the-fly in QGIS.')
raise NoFeaturesInExtentError(myMessage)
myKeywordIO = KeywordIO()
if extra_keywords is None:
extra_keywords = {}
extra_keywords['HAD_MULTIPART_POLY'] = myHasMultipart
myKeywordIO.copy_keywords(
layer, myFilename, extra_keywords=extra_keywords)
myBaseName = '%s clipped' % layer.name()
myLayer = QgsVectorLayer(myFilename, myBaseName, 'ogr')
return myLayer
def _clip_raster_layer(layer, extent, cell_size=None, extra_keywords=None):
"""Clip a Hazard or Exposure raster layer to the extents provided.
The layer must be a raster layer or an exception will be thrown.
.. note:: The extent *must* be in EPSG:4326.
The output layer will always be in WGS84/Geographic.
:param layer: A valid QGIS raster layer in EPSG:4326
:type layer: QgsRasterLayer
:param extent: An array representing the exposure layer
extents in the form [xmin, ymin, xmax, ymax]. It is assumed
that the coordinates are in EPSG:4326 although currently
no checks are made to enforce this.
or:
A QgsGeometry of type polygon.
**Polygon clipping currently only supported for vector datasets.**
:type extent: list(float), QgsGeometry
:param cell_size: Cell size (in GeoCRS) which the layer should
be resampled to. If not provided for a raster layer (i.e.
theCellSize=None), the native raster cell size will be used.
:type cell_size: float
:returns: Output clipped layer (placed in the system temp dir).
:rtype: QgsRasterLayer
:raises: InvalidProjectionError - if input layer is a density
layer in projected coordinates. See issue #123.
"""
if not layer or not extent:
message = tr('Layer or Extent passed to clip is None.')
raise InvalidParameterError(message)
if layer.type() != QgsMapLayer.RasterLayer:
message = tr('Expected a raster layer but received a %s.' %
str(layer.type()))
raise InvalidParameterError(message)
working_layer = str(layer.source())
# Check for existence of keywords file
base, _ = os.path.splitext(working_layer)
keywords_path = base + '.keywords'
message = tr('Input file to be clipped "%s" does not have the '
'expected keywords file %s' % (working_layer, keywords_path))
verify(os.path.isfile(keywords_path), message)
# Raise exception if layer is projected and refers to density (issue #123)
# FIXME (Ole): Need to deal with it - e.g. by automatically reprojecting
# the layer at this point and setting the native resolution accordingly
# in its keywords.
keywords = read_file_keywords(keywords_path)
if 'datatype' in keywords and keywords['datatype'] == 'density':
if str(layer.crs().authid()) != 'EPSG:4326':
# This layer is not WGS84 geographic
message = (
'Layer %s represents density but has spatial reference "%s". '
'Density layers must be given in WGS84 geographic '
'coordinates, so please reproject and try again. For more '
'information, see issue '
'https://github.com/AIFDR/inasafe/issues/123' %
(working_layer, layer.crs().toProj4()))
raise InvalidProjectionError(message)
# We need to provide gdalwarp with a dataset for the clip
# because unline gdal_translate, it does not take projwin.
clip_kml = extent_to_kml(extent)
# Create a filename for the clipped, resampled and reprojected layer
handle, filename = tempfile.mkstemp('.tif', 'clip_', temp_dir())
os.close(handle)
os.remove(filename)
# If no cell size is specified, we need to run gdalwarp without
# specifying the output pixel size to ensure the raster dims
# remain consistent.
binary_list = which('gdalwarp')
LOGGER.debug('Path for gdalwarp: %s' % binary_list)
if len(binary_list) < 1:
raise CallGDALError(tr('gdalwarp could not be found on your computer'))
# Use the first matching gdalwarp found
binary = binary_list[0]
if cell_size is None:
command = (
'"%s" -q -t_srs EPSG:4326 -r near -cutline %s -crop_to_cutline '
'-ot Float64 -of GTiff "%s" "%s"' %
(binary, clip_kml, working_layer, filename))
else:
command = (
'"%s" -q -t_srs EPSG:4326 -r near -tr %f %f -cutline %s '
'-crop_to_cutline -ot Float64 -of GTiff "%s" "%s"' %
(binary, cell_size, cell_size, clip_kml, working_layer, filename))
LOGGER.debug(command)
result = QProcess().execute(command)
# For QProcess exit codes see
# http://qt-project.org/doc/qt-4.8/qprocess.html#execute
if result == -2: # cannot be started
message_detail = tr('Process could not be started.')
message = tr('<p>Error while executing the following shell command:'
'</p><pre>%s</pre><p>Error message: %s' %
(command, message_detail))
raise CallGDALError(message)
elif result == -1: # process crashed
message_detail = tr('Process crashed.')
message = tr(
'<p>Error while executing the following shell command:</p>'
'<pre>%s</pre><p>Error message: %s' % (command, message_detail))
raise CallGDALError(message)
# .. todo:: Check the result of the shell call is ok
keyword_io = KeywordIO()
keyword_io.copy_keywords(layer, filename, extra_keywords=extra_keywords)
base_name = '%s clipped' % layer.name()
layer = QgsRasterLayer(filename, base_name)
return layer