geopyspark.geotrellis.layer module¶
This module contains the RasterLayer and the TiledRasterLayer classes. Both of these
classes are wrappers of their Scala counterparts. These will be used in leau of actual PySpark RDDs
when performing operations.
-
class
geopyspark.geotrellis.layer.RasterLayer(layer_type, srdd)¶ A wrapper of a RDD that contains GeoTrellis rasters.
Represents a layer that wraps a RDD that contains
(K, V). WhereKis eitherProjectedExtentorTemporalProjectedExtentdepending on thelayer_typeof the RDD, andVbeing aTile.The data held within this layer has not been tiled. Meaning the data has yet to be modified to fit a certain layout. See raster_rdd for more information.
Parameters: - layer_type (str or
LayerType) – What the layer type of the geotiffs are. This is represented by either constants withinLayerTypeor by a string. - srdd (py4j.java_gateway.JavaObject) – The coresponding Scala class. This is what allows
RasterLayerto access the various Scala methods.
-
pysc¶ pyspark.SparkContext – The
SparkContextbeing used this session.
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srdd¶ py4j.java_gateway.JavaObject – The coresponding Scala class. This is what allows
RasterLayerto access the various Scala methods.
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bands(band)¶ Select a subsection of bands from the
Tiles within the layer.Note
There could be potential high performance cost if operations are performed between two sub-bands of a large data set.
Note
Due to the natue of GeoPySpark’s backend, if selecting a band that is out of bounds then the error returned will be a
py4j.protocol.Py4JJavaErrorand not a normal Python error.Parameters: band (int or tuple or list or range) – The band(s) to be selected from the Tiles. Can either be a single int, or a collection of ints.Returns: RasterLayerwith the selected bands.
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cache()¶ Persist this RDD with the default storage level (C{MEMORY_ONLY}).
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collect_keys()¶ Returns a list of all of the keys in the layer.
Note
This method should only be called on layers with a smaller number of keys, as a large number could cause memory issues.
Returns: [:obj:`~geopyspark.geotrellis.SpatialKey`]or[:ob:`~geopyspark.geotrellis.SpaceTimeKey`]
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collect_metadata(layout=LocalLayout(tile_cols=256, tile_rows=256))¶ Iterate over the RDD records and generates layer metadata desribing the contained rasters.
- :param layout (
LayoutDefinitionor:GlobalLayoutor LocalLayout, optional):- Target raster layout for the tiling operation.
Returns: Metadata- :param layout (
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convert_data_type(new_type, no_data_value=None)¶ Converts the underlying, raster values to a new
CellType.Parameters: - new_type (str or
CellType) – The data type the cells should be to converted to. - no_data_value (int or float, optional) – The value that should be marked as NoData.
Returns: Raises: ValueError– Ifno_data_valueis set and thenew_typecontains raw values.ValueError– Ifno_data_valueis set andnew_typeis a boolean.
- new_type (str or
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count()¶ Returns how many elements are within the wrapped RDD.
Returns: The number of elements in the RDD. Return type: Int
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filter_by_times(time_intervals)¶ Filters a
SPACETIMElayer by keeping only the values whose keys fall within a the given time interval(s).Parameters: time_intervals ( [datetime.datetime]) – A list of the time intervals to query. This list can have one or multiple elements. If just a single element, then only exact matches with that given time will be kept. If there are multiple times given, then they are each paired together so that they form ranges of time. In the case where there are an odd number of elements, then the remaining time will be treated as a single query and not a range.Note
If nothing intersects the given
time_intervals, then the returnedRasterLayerwill be empty.Returns: RasterLayer
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classmethod
from_numpy_rdd(layer_type, numpy_rdd)¶ Create a
RasterLayerfrom a numpy RDD.Parameters: - layer_type (str or
LayerType) – What the layer type of the geotiffs are. This is represented by either constants withinLayerTypeor by a string. - numpy_rdd (pyspark.RDD) – A PySpark RDD that contains tuples of either
ProjectedExtents orTemporalProjectedExtents and rasters that are represented by a numpy array.
Returns: - layer_type (str or
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getNumPartitions()¶ Returns the number of partitions set for the wrapped RDD.
Returns: The number of partitions. Return type: Int
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get_class_histogram()¶ Creates a
Histogramof integer values. Suitable for classification rasters with limited number values. If only single band is present histogram is returned directly.Returns: Histogramor [Histogram]
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get_histogram()¶ Creates a
Histogramfor each band in the layer. If only single band is present histogram is returned directly.Returns: Histogramor [Histogram]
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get_min_max()¶ Returns the maximum and minimum values of all of the rasters in the layer.
Returns: (float, float)
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get_quantile_breaks(num_breaks)¶ Returns quantile breaks for this Layer.
Parameters: num_breaks (int) – The number of breaks to return. Returns: [float]
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get_quantile_breaks_exact_int(num_breaks)¶ Returns quantile breaks for this Layer. This version uses the
FastMapHistogram, which counts exact integer values. If your layer has too many values, this can cause memory errors.Parameters: num_breaks (int) – The number of breaks to return. Returns: [int]
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isEmpty()¶ Returns a bool that is True if the layer is empty and False if it is not.
Returns: Are there elements within the layer Return type: bool
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map_cells(func)¶ Maps over the cells of each
Tilewithin the layer with a given function.Note
This operation first needs to deserialize the wrapped
RDDinto Python and then serialize theRDDback into aTiledRasterRDDonce the mapping is done. Thus, it is advised to chain together operations to reduce performance cost.Parameters: func (cells, nd => cells) – A function that takes two arguements: cellsandnd. Wherecellsis the numpy array andndis theno_data_valueof theTile. It returnscellswhich are the new cells values of theTilerepresented as a numpy array.Returns: RasterLayer
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map_tiles(func)¶ Maps over each
Tilewithin the layer with a given function.Note
This operation first needs to deserialize the wrapped
RDDinto Python and then serialize theRDDback into aRasterRDDonce the mapping is done. Thus, it is advised to chain together operations to reduce performance cost.Parameters: func ( Tile=>Tile) – A function that takes aTileand returns aTile.Returns: RasterLayer
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merge(num_partitions=None)¶ Merges the
Tileof eachKtogether to produce a singleTile.This method will reduce each value by its key within the layer to produce a single
(K, V)for everyK. In order to achieve this, eachTilethat shares aKis merged together to form a singleTile. This is done by replacing oneTile‘s cells with another’s. Not all cells, if any, may be replaced, however. The following steps are taken to determine if a cell’s value should be replaced:- If the cell contains a
NoDatavalue, then it will be replaced. - If no
NoDatavalue is set, then a cell with a value of 0 will be replaced. - If neither of the above are true, then the cell retain its value.
Parameters: num_partitions (int, optional) – The number of partitions that the resulting layer should be partitioned with. If None, then thenum_partitionswill the number of partitions the layer curretly has.Returns: RasterLayer- If the cell contains a
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persist(storageLevel=StorageLevel(False, True, False, False, 1))¶ Set this RDD’s storage level to persist its values across operations after the first time it is computed. This can only be used to assign a new storage level if the RDD does not have a storage level set yet. If no storage level is specified defaults to (C{MEMORY_ONLY}).
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reclassify(value_map, data_type, classification_strategy=<ClassificationStrategy.LESS_THAN_OR_EQUAL_TO: 'LessThanOrEqualTo'>, replace_nodata_with=None)¶ Changes the cell values of a raster based on how the data is broken up.
Parameters: - value_map (dict) – A
dictwhose keys represent values where a break should occur and its values are the new value the cells within the break should become. - data_type (type) – The type of the values within the rasters. Can either be int or float.
- classification_strategy (str or
ClassificationStrategy, optional) – How the cells should be classified along the breaks. If unspecified, thenClassificationStrategy.LESS_THAN_OR_EQUAL_TOwill be used. - replace_nodata_with (data_type, optional) – When remapping values, nodata values must be treated separately. If nodata values are intended to be replaced during the reclassify, this variable should be set to the intended value. If unspecified, nodata values will be preserved.
Note
NoData symbolizes a different value depending on if
data_typeis int or float. For int, the constantNO_DATA_INTcan be used which represents the NoData value for int in GeoTrellis. For float,float('nan')is used to represent NoData.Returns: RasterLayer- value_map (dict) – A
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reproject(target_crs, resample_method=<ResampleMethod.NEAREST_NEIGHBOR: 'NearestNeighbor'>)¶ Reproject rasters to
target_crs. The reproject does not sample past tile boundary.Parameters: - target_crs (str or int) – Target CRS of reprojection. Either EPSG code, well-known name, or a PROJ.4 string.
- resample_method (str or
ResampleMethod, optional) – The resample method to use for the reprojection. If none is specified, thenResampleMethods.NEAREST_NEIGHBORis used.
Returns:
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tile_to_layout(layout=LocalLayout(tile_cols=256, tile_rows=256), target_crs=None, resample_method=<ResampleMethod.NEAREST_NEIGHBOR: 'NearestNeighbor'>)¶ Cut tiles to layout and merge overlapping tiles. This will produce unique keys.
- :param layout (
Metadataor:TiledRasterLayeror LayoutDefinitionorGlobalLayoutorLocalLayout, optional):Target raster layout for the tiling operation.
Parameters: - target_crs (str or int, optional) – Target CRS of reprojection. Either EPSG code,
well-known name, or a PROJ.4 string. If
None, no reproject will be perfomed. - resample_method (str or
ResampleMethod, optional) – The cell resample method to used during the tiling operation. Default is``ResampleMethods.NEAREST_NEIGHBOR``.
Returns: - :param layout (
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to_geotiff_rdd(storage_method=<StorageMethod.STRIPED: 'Striped'>, rows_per_strip=None, tile_dimensions=(256, 256), compression=<Compression.NO_COMPRESSION: 'NoCompression'>, color_space=<ColorSpace.BLACK_IS_ZERO: 1>, color_map=None, head_tags=None, band_tags=None)¶ Converts the rasters within this layer to GeoTiffs which are then converted to bytes. This is returned as a
RDD[(K, bytes)]. WhereKis eitherProjectedExtentorTemporalProjectedExtent.Parameters: - storage_method (str or
StorageMethod, optional) – How the segments within the GeoTiffs should be arranged. Default isStorageMethod.STRIPED. - rows_per_strip (int, optional) – How many rows should be in each strip segment of the
GeoTiffs if
storage_methodisStorageMethod.STRIPED. IfNone, then the strip size will default to a value that is 8K or less. - tile_dimensions ((int, int), optional) – The length and width for each tile segment of the GeoTiff
if
storage_methodisStorageMethod.TILED. IfNonethen the default size is(256, 256). - compression (str or
Compression, optional) – How the data should be compressed. Defaults toCompression.NO_COMPRESSION. - color_space (str or
ColorSpace, optional) – How the colors should be organized in the GeoTiffs. Defaults toColorSpace.BLACK_IS_ZERO. - color_map (
ColorMap, optional) – AColorMapinstance used to color the GeoTiffs to a different gradient. - head_tags (dict, optional) – A
dictwhere each key and value is astr. - band_tags (list, optional) – A
listofdicts where each key and value is astr. - Note – For more information on the contents of the tags, see www.gdal.org/gdal_datamodel.html
Returns: RDD[(K, bytes)]
- storage_method (str or
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to_numpy_rdd()¶ Converts a
RasterLayerto a numpy RDD.Note
Depending on the size of the data stored within the RDD, this can be an exspensive operation and should be used with caution.
Returns: RDD
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to_png_rdd(color_map)¶ Converts the rasters within this layer to PNGs which are then converted to bytes. This is returned as a RDD[(K, bytes)].
Parameters: color_map ( ColorMap) – AColorMapinstance used to color the PNGs.Returns: RDD[(K, bytes)]
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to_spatial_layer(target_time=None)¶ Converts a
RasterLayerwith alayout_typeofLayoutType.SPACETIMEto aRasterLayerwith alayout_typeofLayoutType.SPATIAL.Parameters: target_time ( datetime.datetime, optional) – The instance of interest. If set, the resultingRasterLayerwill only contain keys that contained the given instance. IfNone, then all values within the layer will be kept.Returns: RasterLayerRaises: ValueError– If the layer already has alayout_typeofLayoutType.SPATIAL.
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unpersist()¶ Mark the RDD as non-persistent, and remove all blocks for it from memory and disk.
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wrapped_rdds()¶ Returns the list of RDD-containing objects wrapped by this object. The default implementation assumes that subclass contains a single RDD container, srdd, which implements the persist() and unpersist() methods.
- layer_type (str or
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class
geopyspark.geotrellis.layer.TiledRasterLayer(layer_type, srdd)¶ Wraps a RDD of tiled, GeoTrellis rasters.
Represents a RDD that contains
(K, V). WhereKis eitherSpatialKeyorSpaceTimeKeydepending on thelayer_typeof the RDD, andVbeing aTile.The data held within the layer is tiled. This means that the rasters have been modified to fit a larger layout. For more information, see tiled-raster-rdd.
Parameters: - layer_type (str or
LayerType) – What the layer type of the geotiffs are. This is represented by either constants withinLayerTypeor by a string. - srdd (py4j.java_gateway.JavaObject) – The coresponding Scala class. This is what allows
TiledRasterLayerto access the various Scala methods.
-
pysc¶ pyspark.SparkContext – The
SparkContextbeing used this session.
-
srdd¶ py4j.java_gateway.JavaObject – The coresponding Scala class. This is what allows
RasterLayerto access the various Scala methods.
-
is_floating_point_layer¶ bool – Whether the data within the
TiledRasterLayeris floating point or not.
-
zoom_level¶ int – The zoom level of the layer. Can be
None.
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aggregate_by_cell(operation)¶ Computes an aggregate summary for each cell of all of the values for each key.
The
operationgiven is a local map algebra function that will be applied to all values that share the same key. If there are multiple copies of the same key in the layer, then this method will reduce all instances of the(K, Tile)pairs into a single element. This resulting(K, Tile)‘sTilewill contain the aggregate summaries of each cell of the reducedTiles that had the sameK.Note
Not all
Operations are supported. OnlySUM,MIN,MAX,MEAN,VARIANCE, ANDSTANDARD_DEVIATIONcan be used.Note
If calculating
VARIANCEorSTANDARD_DEVIATION, then anyKthat is a single copy will have a resultingTilethat is filled withNoDatavalues. This is because the variance of a single element is undefined.Parameters: operation (str or Operation) – The aggregate operation to be performed.Returns: TiledRasterLayer
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bands(band)¶ Select a subsection of bands from the
Tiles within the layer.Note
There could be potential high performance cost if operations are performed between two sub-bands of a large data set.
Note
Due to the natue of GeoPySpark’s backend, if selecting a band that is out of bounds then the error returned will be a
py4j.protocol.Py4JJavaErrorand not a normal Python error.Parameters: band (int or tuple or list or range) – The band(s) to be selected from the Tiles. Can either be a single int, or a collection of ints.Returns: TiledRasterLayerwith the selected bands.
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cache()¶ Persist this RDD with the default storage level (C{MEMORY_ONLY}).
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collect_keys()¶ Returns a list of all of the keys in the layer.
Note
This method should only be called on layers with a smaller number of keys, as a large number could cause memory issues.
Returns: [:class:`~geopyspark.geotrellis.ProjectedExtent`]or[:class:`~geopyspark.geotrellis.TemporalProjectedExtent`]
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convert_data_type(new_type, no_data_value=None)¶ Converts the underlying, raster values to a new
CellType.Parameters: - new_type (str or
CellType) – The data type the cells should be to converted to. - no_data_value (int or float, optional) – The value that should be marked as NoData.
Returns: Raises: ValueError– Ifno_data_valueis set and thenew_typecontains raw values.ValueError– Ifno_data_valueis set andnew_typeis a boolean.
- new_type (str or
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count()¶ Returns how many elements are within the wrapped RDD.
Returns: The number of elements in the RDD. Return type: Int
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filter_by_times(time_intervals)¶ Filters a
SPACETIMElayer by keeping only the values whose keys fall within a the given time interval(s).Parameters: time_intervals ( [datetime.datetime]) – A list of the time intervals to query. This list can have one or multiple elements. If just a single element, then only exact matches with that given time will be kept. If there are multiple times given, then they are each paired together so that they form ranges of time. In the case where there are an odd number of elements, then the remaining time will be treated as a single query and not a range.Note
If nothing intersects the given
time_intervals, then the returnedTiledRasterLayerwill be empty.Returns: TiledRasterLayer
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focal(operation, neighborhood=None, param_1=None, param_2=None, param_3=None)¶ Performs the given focal operation on the layers contained in the Layer.
Parameters: - operation (str or
Operation) – The focal operation to be performed. - neighborhood (str or
Neighborhood, optional) – The type of neighborhood to use in the focal operation. This can be represented by either an instance ofNeighborhood, or by a constant. - param_1 (int or float, optional) – If using
Operation.SLOPE, then this is the zFactor, else it is the first argument ofneighborhood. - param_2 (int or float, optional) – The second argument of the
neighborhood. - param_3 (int or float, optional) – The third argument of the
neighborhood.
Note
paramonly need to be set ifneighborhoodis not an instance ofNeighborhoodor ifneighborhoodisNone.Any
paramthat is not set will default to 0.0.If
neighborhoodisNonethenoperationmust be eitherOperation.SLOPEorOperation.ASPECT.Returns: Raises: ValueError– Ifoperationis not a known operation.ValueError– Ifneighborhoodis not a known neighborhood.ValueError– Ifneighborhoodwas not set, andoperationis notOperation.SLOPEorOperation.ASPECT.
- operation (str or
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classmethod
from_numpy_rdd(layer_type, numpy_rdd, metadata, zoom_level=None)¶ Create a
TiledRasterLayerfrom a numpy RDD.Parameters: - layer_type (str or
LayerType) – What the layer type of the geotiffs are. This is represented by either constants withinLayerTypeor by a string. - numpy_rdd (pyspark.RDD) – A PySpark RDD that contains tuples of either
SpatialKeyorSpaceTimeKeyand rasters that are represented by a numpy array. - metadata (
Metadata) – TheMetadataof theTiledRasterLayerinstance. - zoom_level (int, optional) – The
zoom_levelthe resulting TiledRasterLayer should have. IfNone, then the returned layer’szoom_levelwill beNone.
Returns: - layer_type (str or
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getNumPartitions()¶ Returns the number of partitions set for the wrapped RDD.
Returns: The number of partitions. Return type: Int
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get_class_histogram()¶ Creates a
Histogramof integer values. Suitable for classification rasters with limited number values. If only single band is present histogram is returned directly.Returns: Histogramor [Histogram]
-
get_histogram()¶ Creates a
Histogramfor each band in the layer. If only single band is present histogram is returned directly.Returns: Histogramor [Histogram]
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get_min_max()¶ Returns the maximum and minimum values of all of the rasters in the layer.
Returns: (float, float)
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get_point_values(points, resample_method=None)¶ Returns the values of the layer at given points.
Note
Only points that are contained within a layer will be sampled. This means that if a point lies on the southern or eastern boundary of a cell, it will not be sampled.
Parameters: - or {k (points([shapely.geometry.Point]) – shapely.geometry.Point}):
Either a list of, or a dictionary whose values are
shapely.geometry.Points. If a dictionary, then the type of its keys does not matter. These points must be in the same projection as the tiles within the layer. - resample_method (str or
ResampleMethod, optional) –The resampling method to use before obtaining the point values. If not specified, then
Noneis used.Note
Not all
ResampleMethods can be used to resample point values.ResampleMethod.NEAREST_NEIGHBOR,ResampleMethod.BILINEAR`,ResampleMethod.CUBIC_CONVOLUTION, andResampleMethod.CUBIC_SPLINEare the only ones that can be used.
Returns: The return type will vary depending on the type of
pointsand thelayer_typeof the sampled layer.- If
pointsis alistand thelayer_typeisSPATIAL: [(shapely.geometry.Point, [float])]
- If
pointsis alistand thelayer_typeisSPACETIME: [(shapely.geometry.Point, datetime.datetime, [float])]
- If
pointsis adictand thelayer_typeisSPATIAL: {k: (shapely.geometry.Point, [float])}
- If
pointsis adictand thelayer_typeisSPACETIME: {k: (shapely.geometry.Point, datetime.datetime, [float])}
The
shapely.geometry.Pointin all of these returns is the original sampled point given. The[float]are the sampled values, one for each band. If thelayer_typewasSPACETIME, then the timestamp will also be included in the results represented by adatetime.datetimeinstance.Note
The sampled values will always be returned as
floats. Regardless of thecellTypeof the layer.If
pointswas given as adictthen the keys of that dictionary will be the keys in the returneddict.- or {k (points([shapely.geometry.Point]) – shapely.geometry.Point}):
Either a list of, or a dictionary whose values are
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get_quantile_breaks(num_breaks)¶ Returns quantile breaks for this Layer.
Parameters: num_breaks (int) – The number of breaks to return. Returns: [float]
-
get_quantile_breaks_exact_int(num_breaks)¶ Returns quantile breaks for this Layer. This version uses the
FastMapHistogram, which counts exact integer values. If your layer has too many values, this can cause memory errors.Parameters: num_breaks (int) – The number of breaks to return. Returns: [int]
-
isEmpty()¶ Returns a bool that is True if the layer is empty and False if it is not.
Returns: Are there elements within the layer Return type: bool
-
lookup(col, row)¶ Return the value(s) in the image of a particular
SpatialKey(given by col and row).Parameters: - col (int) – The
SpatialKeycolumn. - row (int) – The
SpatialKeyrow.
Returns: [
Tile]Raises: ValueError– If using lookup on a nonLayerType.SPATIALTiledRasterLayer.IndexError– If col and row are not within theTiledRasterLayer‘s bounds.
- col (int) – The
-
map_cells(func)¶ Maps over the cells of each
Tilewithin the layer with a given function.Note
This operation first needs to deserialize the wrapped
RDDinto Python and then serialize theRDDback into aTiledRasterRDDonce the mapping is done. Thus, it is advised to chain together operations to reduce performance cost.Parameters: func (cells, nd => cells) – A function that takes two arguements: cellsandnd. Wherecellsis the numpy array andndis theno_data_valueof the tile. It returnscellswhich are the new cells values of the tile represented as a numpy array.Returns: TiledRasterLayer
-
map_tiles(func)¶ Maps over each
Tilewithin the layer with a given function.Note
This operation first needs to deserialize the wrapped
RDDinto Python and then serialize theRDDback into aTiledRasterRDDonce the mapping is done. Thus, it is advised to chain together operations to reduce performance cost.Parameters: func ( Tile=>Tile) – A function that takes aTileand returns aTile.Returns: TiledRasterLayer
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mask(geometries)¶ Masks the
TiledRasterLayerso that only values that intersect the geometries will be available.Parameters: geometries (shapely.geometry or [shapely.geometry]) – Either a list of, or a single shapely geometry/ies to use for the mask/s.
Note
All geometries must be in the same CRS as the TileLayer.
Returns: TiledRasterLayer
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merge(num_partitions=None)¶ Merges the
Tileof eachKtogether to produce a singleTile.This method will reduce each value by its key within the layer to produce a single
(K, V)for everyK. In order to achieve this, eachTilethat shares aKis merged together to form a singleTile. This is done by replacing oneTile‘s cells with another’s. Not all cells, if any, may be replaced, however. The following steps are taken to determine if a cell’s value should be replaced:- If the cell contains a
NoDatavalue, then it will be replaced. - If no
NoDatavalue is set, then a cell with a value of 0 will be replaced. - If neither of the above are true, then the cell retain its value.
Parameters: num_partitions (int, optional) – The number of partitions that the resulting layer should be partitioned with. If None, then thenum_partitionswill the number of partitions the layer curretly has.Returns: TiledRasterLayer- If the cell contains a
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normalize(new_min, new_max, old_min=None, old_max=None)¶ Finds the min value that is contained within the given geometry.
Note
If
old_max - old_min <= 0ornew_max - new_min <= 0, then the normalization will fail.Parameters: - old_min (int or float, optional) – Old minimum. If not given, then the minimum value of this layer will be used.
- old_max (int or float, optional) – Old maximum. If not given, then the minimum value of this layer will be used.
- new_min (int or float) – New minimum to normalize to.
- new_max (int or float) – New maximum to normalize to.
Returns:
-
persist(storageLevel=StorageLevel(False, True, False, False, 1))¶ Set this RDD’s storage level to persist its values across operations after the first time it is computed. This can only be used to assign a new storage level if the RDD does not have a storage level set yet. If no storage level is specified defaults to (C{MEMORY_ONLY}).
-
polygonal_max(geometry, data_type)¶ Finds the max value for each band that is contained within the given geometry.
Parameters: - geometry (shapely.geometry.Polygon or shapely.geometry.MultiPolygon or bytes) – A
Shapely
PolygonorMultiPolygonthat represents the area where the summary should be computed; or a WKB representation of the geometry. - data_type (type) – The type of the values within the rasters. Can either be int or float.
Returns: [int] or [float] depending on
data_type.Raises: TypeError– Ifdata_typeis not an int or float.- geometry (shapely.geometry.Polygon or shapely.geometry.MultiPolygon or bytes) – A
Shapely
-
polygonal_mean(geometry)¶ Finds the mean of all of the values for each band that are contained within the given geometry.
Parameters: geometry (shapely.geometry.Polygon or shapely.geometry.MultiPolygon or bytes) – A Shapely PolygonorMultiPolygonthat represents the area where the summary should be computed; or a WKB representation of the geometry.Returns: [float]
-
polygonal_min(geometry, data_type)¶ Finds the min value for each band that is contained within the given geometry.
Parameters: - geometry (shapely.geometry.Polygon or shapely.geometry.MultiPolygon or bytes) – A
Shapely
PolygonorMultiPolygonthat represents the area where the summary should be computed; or a WKB representation of the geometry. - data_type (type) – The type of the values within the rasters. Can either be int or float.
Returns: [int] or [float] depending on
data_type.Raises: TypeError– Ifdata_typeis not an int or float.- geometry (shapely.geometry.Polygon or shapely.geometry.MultiPolygon or bytes) – A
Shapely
-
polygonal_sum(geometry, data_type)¶ Finds the sum of all of the values in each band that are contained within the given geometry.
Parameters: - geometry (shapely.geometry.Polygon or shapely.geometry.MultiPolygon or bytes) – A
Shapely
PolygonorMultiPolygonthat represents the area where the summary should be computed; or a WKB representation of the geometry. - data_type (type) – The type of the values within the rasters. Can either be int or float.
Returns: [int] or [float] depending on
data_type.Raises: TypeError– Ifdata_typeis not an int or float.- geometry (shapely.geometry.Polygon or shapely.geometry.MultiPolygon or bytes) – A
Shapely
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pyramid(resample_method=<ResampleMethod.NEAREST_NEIGHBOR: 'NearestNeighbor'>)¶ Creates a layer
Pyramidwhere the resolution is halved per level.Parameters: resample_method (str or ResampleMethod, optional) – The resample method to use when building the pyramid. Default isResampleMethods.NEAREST_NEIGHBOR.Returns: Pyramid.Raises: ValueError– If this layer layout is not ofGlobalLayouttype.
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reclassify(value_map, data_type, classification_strategy=<ClassificationStrategy.LESS_THAN_OR_EQUAL_TO: 'LessThanOrEqualTo'>, replace_nodata_with=None)¶ Changes the cell values of a raster based on how the data is broken up.
Parameters: - value_map (dict) – A
dictwhose keys represent values where a break should occur and its values are the new value the cells within the break should become. - data_type (type) – The type of the values within the rasters. Can either be int or float.
- classification_strategy (str or
ClassificationStrategy, optional) – How the cells should be classified along the breaks. If unspecified, thenClassificationStrategy.LESS_THAN_OR_EQUAL_TOwill be used. - replace_nodata_with (data_type, optional) – When remapping values, nodata values must be treated separately. If nodata values are intended to be replaced during the reclassify, this variable should be set to the intended value. If unspecified, nodata values will be preserved.
Note
NoData symbolizes a different value depending on if
data_typeis int or float. For int, the constantNO_DATA_INTcan be used which represents the NoData value for int in GeoTrellis. For float,float('nan')is used to represent NoData.Returns: TiledRasterLayer- value_map (dict) – A
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repartition(num_partitions=None)¶ Repartition underlying RDD using HashPartitioner. If
num_partitionsis None, existing number of partitions will be used.Parameters: num_partitions (int, optional) – Desired number of partitions Returns: TiledRasterLayer
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reproject(target_crs, resample_method=<ResampleMethod.NEAREST_NEIGHBOR: 'NearestNeighbor'>)¶ Reproject rasters to
target_crs. The reproject does not sample past tile boundary.Parameters: - target_crs (str or int) – Target CRS of reprojection. Either EPSG code, well-known name, or a PROJ.4 string.
- resample_method (str or
ResampleMethod, optional) – The resample method to use for the reprojection. If none is specified, thenResampleMethods.NEAREST_NEIGHBORis used.
Returns:
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save_stitched(path, crop_bounds=None, crop_dimensions=None)¶ Stitch all of the rasters within the Layer into one raster and then saves it to a given path.
Parameters: - path (str) – The path of the geotiff to save. The path must be on the local file system.
- crop_bounds (
Extent, optional) – The subExtentwith which to crop the raster before saving. IfNone, then the whole raster will be saved. - crop_dimensions (tuple(int) or list(int), optional) – cols and rows of the image to save
represented as either a tuple or list. If
Nonethen all cols and rows of the raster will be save.
Note
This can only be used on
LayerType.SPATIALTiledRasterLayers.Note
If
crop_dimensionsis set thencrop_boundsmust also be set.
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stitch()¶ Stitch all of the rasters within the Layer into one raster.
Note
This can only be used on
LayerType.SPATIALTiledRasterLayers.Returns: Tile
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tile_to_layout(layout, target_crs=None, resample_method=<ResampleMethod.NEAREST_NEIGHBOR: 'NearestNeighbor'>)¶ Cut tiles to a given layout and merge overlapping tiles. This will produce unique keys.
- :param layout (
LayoutDefinitionor:Metadataor TiledRasterLayerorGlobalLayoutorLocalLayout):Target raster layout for the tiling operation.
Parameters: - target_crs (str or int, optional) – Target CRS of reprojection. Either EPSG code,
well-known name, or a PROJ.4 string. If
None, no reproject will be perfomed. - resample_method (str or
ResampleMethod, optional) – The resample method to use for the reprojection. If none is specified, thenResampleMethods.NEAREST_NEIGHBORis used.
Returns: - :param layout (
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to_geotiff_rdd(storage_method=<StorageMethod.STRIPED: 'Striped'>, rows_per_strip=None, tile_dimensions=(256, 256), compression=<Compression.NO_COMPRESSION: 'NoCompression'>, color_space=<ColorSpace.BLACK_IS_ZERO: 1>, color_map=None, head_tags=None, band_tags=None)¶ Converts the rasters within this layer to GeoTiffs which are then converted to bytes. This is returned as a
RDD[(K, bytes)]. WhereKis eitherSpatialKeyorSpaceTimeKey.Parameters: - storage_method (str or
StorageMethod, optional) – How the segments within the GeoTiffs should be arranged. Default isStorageMethod.STRIPED. - rows_per_strip (int, optional) – How many rows should be in each strip segment of the
GeoTiffs if
storage_methodisStorageMethod.STRIPED. IfNone, then the strip size will default to a value that is 8K or less. - tile_dimensions ((int, int), optional) – The length and width for each tile segment of the GeoTiff
if
storage_methodisStorageMethod.TILED. IfNonethen the default size is(256, 256). - compression (str or
Compression, optional) – How the data should be compressed. Defaults toCompression.NO_COMPRESSION. - color_space (str or
ColorSpace, optional) – How the colors should be organized in the GeoTiffs. Defaults toColorSpace.BLACK_IS_ZERO. - color_map (
ColorMap, optional) – AColorMapinstance used to color the GeoTiffs to a different gradient. - head_tags (dict, optional) – A
dictwhere each key and value is astr. - band_tags (list, optional) – A
listofdicts where each key and value is astr. - Note – For more information on the contents of the tags, see www.gdal.org/gdal_datamodel.html
Returns: RDD[(K, bytes)]
- storage_method (str or
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to_numpy_rdd()¶ Converts a
TiledRasterLayerto a numpy RDD.Note
Depending on the size of the data stored within the RDD, this can be an exspensive operation and should be used with caution.
Returns: RDD
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to_png_rdd(color_map)¶ Converts the rasters within this layer to PNGs which are then converted to bytes. This is returned as a RDD[(K, bytes)].
Parameters: color_map ( ColorMap) – AColorMapinstance used to color the PNGs.Returns: RDD[(K, bytes)]
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to_spatial_layer(target_time=None)¶ Converts a
TiledRasterLayerwith alayout_typeofLayoutType.SPACETIMEto aTiledRasterLayerwith alayout_typeofLayoutType.SPATIAL.Parameters: target_time ( datetime.datetime, optional) – The instance of interest. If set, the resultingTiledRasterLayerwill only contain keys that contained the given instance. IfNone, then all values within the layer will be kept.Returns: TiledRasterLayerRaises: ValueError– If the layer already has alayout_typeofLayoutType.SPATIAL.
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unpersist()¶ Mark the RDD as non-persistent, and remove all blocks for it from memory and disk.
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wrapped_rdds()¶ Returns the list of RDD-containing objects wrapped by this object. The default implementation assumes that subclass contains a single RDD container, srdd, which implements the persist() and unpersist() methods.
- layer_type (str or
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class
geopyspark.geotrellis.layer.Pyramid(levels)¶ Contains a list of
TiledRasterLayers that make up a tile pyramid. Each layer represents a level within the pyramid. This class is used when creating a tile server.Map algebra can performed on instances of this class.
Parameters: levels (list or dict) – A list of TiledRasterLayers or a dict ofTiledRasterLayers where the value is the layer itself and the key is its given zoom level.-
pysc¶ pyspark.SparkContext – The
SparkContextbeing used this session.
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layer_type (class ~geopyspark.geotrellis.constants.LayerType): What the layer type of the geotiffs are.
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levels¶ dict – A dict of
TiledRasterLayers where the value is the layer itself and the key is its given zoom level.
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max_zoom¶ int – The highest zoom level of the pyramid.
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is_cached¶ bool – Signals whether or not the internal RDDs are cached. Default is
False.
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histogram¶ Histogram– TheHistogramthat represents the layer with the max zoomw. Will not be calculated unless theget_histogram()method is used. Otherwise, its value isNone.
Raises: TypeError– Iflevelsis neither a list or dict.-
cache()¶ Persist this RDD with the default storage level (C{MEMORY_ONLY}).
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count()¶ Returns how many elements are within the wrapped RDD.
Returns: The number of elements in the RDD. Return type: Int
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getNumPartitions()¶ Returns the number of partitions set for the wrapped RDD.
Returns: The number of partitions. Return type: Int
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isEmpty()¶ Returns a bool that is True if the layer is empty and False if it is not.
Returns: Are there elements within the layer Return type: bool
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persist(storageLevel=StorageLevel(False, True, False, False, 1))¶ Set this RDD’s storage level to persist its values across operations after the first time it is computed. This can only be used to assign a new storage level if the RDD does not have a storage level set yet. If no storage level is specified defaults to (C{MEMORY_ONLY}).
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unpersist()¶ Mark the RDD as non-persistent, and remove all blocks for it from memory and disk.
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wrapped_rdds()¶ Returns a list of the wrapped, Scala RDDs within each layer of the pyramid.
Returns: [org.apache.spark.rdd.RDD]
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