exactextract.exact_extract
==========================

.. py:module:: exactextract.exact_extract


Functions
---------

.. autoapisummary::

   exactextract.exact_extract.exact_extract


Module Contents
---------------

.. py:function:: exact_extract(rast, vec, ops, *, weights=None, include_cols=None, include_geom=False, strategy: str = 'feature-sequential', max_cells_in_memory: int = 30000000, grid_compat_tol: float = 0.001, output: str = 'geojson', output_options: Optional[Mapping] = None, progress=False)

   Calculate zonal statistics.

   :param rast: One or a list of :py:class:`RasterSource` object(s) or filename(s) that
                can be opened by GDAL/rasterio/xarray.
   :param vec: A :py:class:`FeatureSource` or filename that can be opened
               by GDAL/fiona
   :param ops: A list of :py:class:`Operation` objects, or strings that
               can be used to construct them (e.g., ``"mean"``, ``"quantile(q=0.33)"``).
               Check out :doc:`Available operations </operations>` for more information.
   :param weights: An optional :py:class:`RasterSource` or filename for
                   weights to be used in weighted operations.
   :param include_cols: An optional list of columns from the
                        input features to be included into the output.
   :param include_geom: Flag indicating whether the geometry
                        should be copied from the input features into
                        the output.
   :param strategy: Specifies the strategy to use when processing features.
                    Detailed performance notes are available in
                    :ref:`Performance - Processing strategies <performance-processing-strategies>`.
                    Must be set to one of:

                           - ``"feature-sequential"`` (the default):
                             iterate over the features in ``vec``,
                             read the corresponding pixels from ``rast``/``weights``,
                             and compute the summary operations. This offers predictable
                             memory consumption but may be inefficient if the order of
                             features in ``vec`` causes the same, relatively large raster
                             blocks to be read and decompressed many times.

                           - ``"raster-sequential"``:
                             iterate over chunks of pixels in ``rast``, identify the intersecting
                             features from ``vec``, and compute statistics. This performs better
                             than ``strategy="feature-sequential"`` in some cases, but comes at
                             a cost of higher memory usage.
   :param max_cells_in_memory: Indicates the maximum number of raster cells that should be
                               loaded into memory at a given time.
   :param grid_compat_tol: require value and weight grids to align within ``grid_compat_tol`` times the smaller of the two grid resolutions
   :param output: An :py:class:`OutputWriter` or one of the following strings:

                  - "geojson" (the default): return a list of GeoJSON-like features
                  - "pandas": return a ``pandas.DataFrame`` or ``geopandas.GeoDataFrame``,
                              depending on the value of ``include_geom``
                  - "gdal": write results to disk using GDAL/OGR as they are written. This
                            option (with ``strategy="feature-sequential"``) avoids the need
                            to maintain results for all features in memory at a single time,
                            which may be significant for operations with large result sizes
                            such as ``cell_id``, ``values``, etc.
   :param output_options: an optional dictionary of options passed to the :py:class:`writer.JSONWriter`, :py:class:`writer.PandasWriter`, or :py:class:`writer.GDALWriter`.
   :param progress: if `True`, a progress bar will be displayed. Alternatively, a
                    function may be provided that will be called with the completion fraction
                    and a status message.