DAS-2232 -small functions added to support the main solution in the t…

docs/requirements.txt

@@ -16,5 +16,5 @@
 #
 harmony-py~=0.4.10
 netCDF4~=1.6.4
-notebook~=7.0.4
+notebook~=7.2.2
 xarray~=2023.9.0

hoss/coordinate_utilities.py

@@ -0,0 +1,210 @@
+""" This module contains utility functions used for
+    coordinate variables and functions to convert the
+    coordinate variable data to projected x/y dimension values
+"""
+
+import numpy as np
+from netCDF4 import Dataset
+
+# from numpy import ndarray
+from varinfo import VariableFromDmr, VarInfoFromDmr
+
+from hoss.exceptions import (
+    IncompatibleCoordinateVariables,
+    InvalidCoordinateDataset,
+    InvalidCoordinateVariable,
+    MissingCoordinateVariable,
+    MissingVariable,
+)
+
+
+def get_projected_dimension_names(varinfo: VarInfoFromDmr, variable_name: str) -> str:
+    """returns the x-y projection variable names that would
+    match the group of the input variable. The 'projected_y' dimension
+    and 'projected_x' names are returned with the group pathname
+
+    """
+    variable = varinfo.get_variable(variable_name)
+
+    if variable is not None:
+        projected_dimension_names = [
+            f'{variable.group_path}/projected_y',
+            f'{variable.group_path}/projected_x',
+        ]
+    else:
+        raise MissingVariable(variable_name)
+
+    return projected_dimension_names
+
+
+def get_projected_dimension_names_from_coordinate_variables(
+    varinfo: VarInfoFromDmr,
+    variable_name: str,
+) -> list[str]:
+    """
+    Returns the projected dimensions names from coordinate variables
+    """
+    latitude_coordinates, longitude_coordinates = get_coordinate_variables(
+        varinfo, [variable_name]
+    )
+
+    if len(latitude_coordinates) == 1 and len(longitude_coordinates) == 1:
+        projected_dimension_names = get_projected_dimension_names(
+            varinfo, latitude_coordinates[0]
+        )
+
+    # if the override is the variable
+    elif (
+        varinfo.get_variable(variable_name).is_latitude()
+        or varinfo.get_variable(variable_name).is_longitude()
+    ):
+        projected_dimension_names = get_projected_dimension_names(
+            varinfo, variable_name
+        )
+    else:
+        projected_dimension_names = []
+    return projected_dimension_names
+
+
+def get_variables_with_anonymous_dims(
+    varinfo: VarInfoFromDmr, variables: set[str]
+) -> set[str]:
+    """
+    returns a set of variables without any dimensions
+    associated with it
+    """
+
+    return set(
+        variable
+        for variable in variables
+        if len(varinfo.get_variable(variable).dimensions) == 0
+    )
+
+
+def get_coordinate_variables(
+    varinfo: VarInfoFromDmr,
+    requested_variables: list,
+) -> tuple[list, list]:
+    """This function returns latitude and longitude variables listed in the
+    CF-Convention coordinates metadata attribute. It returns them in a specific
+    order [latitude, longitude]"
+    """
+
+    coordinate_variables_list = varinfo.get_references_for_attribute(
+        requested_variables, 'coordinates'
+    )
+    latitude_coordinate_variables = [
+        coordinate
+        for coordinate in coordinate_variables_list
+        if varinfo.get_variable(coordinate).is_latitude()
+    ]
+
+    longitude_coordinate_variables = [
+        coordinate
+        for coordinate in coordinate_variables_list
+        if varinfo.get_variable(coordinate).is_longitude()
+    ]
+
+    return latitude_coordinate_variables, longitude_coordinate_variables
+
+
+def get_row_col_sizes_from_coordinate_datasets(
+    lat_arr: np.ndarray,
+    lon_arr: np.ndarray,
+) -> tuple[int, int]:
+    """
+    This function returns the row and column sizes of the coordinate datasets
+
+    """
+    # ToDo - if the coordinates are 3D
+    if lat_arr.ndim > 1 and lon_arr.shape == lat_arr.shape:
+        col_size = lat_arr.shape[1]
+        row_size = lat_arr.shape[0]
+    elif (
+        lat_arr.ndim == 1
+        and lon_arr.ndim == 1
+        and lat_arr.size > 0
+        and lon_arr.size > 0
+    ):
+        # Todo: The ordering needs to be checked
+        col_size = lon_arr.size
+        row_size = lat_arr.size
+    else:
+        raise IncompatibleCoordinateVariables(lon_arr.shape, lat_arr.shape)
+    return row_size, col_size
+
+
+def get_coordinate_array(
+    prefetch_dataset: Dataset,
+    coordinate_name: str,
+) -> np.ndarray:
+    """This function returns the `numpy` array from a
+    coordinate dataset.
+
+    """
+    try:
+        coordinate_array = prefetch_dataset[coordinate_name][:]
+    except IndexError as exception:
+        raise MissingCoordinateVariable(coordinate_name) from exception
+
+    return coordinate_array
+
+
+def get_1D_dim_array_data_from_dimvalues(
+    dim_values: np.ndarray, dim_indices: np.ndarray, dim_size: int
+) -> np.ndarray:
+    """
+    return a full dimension data array based on the 2 projected points and
+    grid size
+    """
+
+    if (dim_indices[1] != dim_indices[0]) and (dim_values[1] != dim_values[0]):
+        dim_resolution = (dim_values[1] - dim_values[0]) / (
+            dim_indices[1] - dim_indices[0]
+        )
+    else:
+        raise InvalidCoordinateDataset(dim_values[0], dim_indices[0])
+
+    dim_min = dim_values[0] - (dim_resolution * dim_indices[0])
+    dim_max = dim_values[1] + (dim_resolution * (dim_size - 1 - dim_indices[1]))
+    return np.linspace(dim_min, dim_max, dim_size)
+
+
+def get_valid_indices(
+    coordinate_row_col: np.ndarray, coordinate: VariableFromDmr
+) -> np.ndarray:
+    """
+    Returns indices of a valid array without fill values if the fill
+    value is provided. If it is not provided, we check for valid values
+    for latitude and longitude
+    """
+
+    coordinate_fill = coordinate.get_attribute_value('_FillValue')
+    if coordinate_fill:
+        valid_indices = np.where(
+            ~np.isclose(coordinate_row_col, float(coordinate_fill))
+        )[0]
+    else:
+        valid_indices = np.where(coordinate_row_col)[0]
+
+    if coordinate.is_longitude():
+        filtered_valid_indices = np.array(
+            [
+                index
+                for index in valid_indices
+                if coordinate_row_col[index] >= -180.0
+                and coordinate_row_col[index] <= 360.0
+            ]
+        )
+    elif coordinate.is_latitude():
+        filtered_valid_indices = np.array(
+            [
+                index
+                for index in valid_indices
+                if coordinate_row_col[index] >= -90.0
+                and coordinate_row_col[index] <= 90.0
+            ]
+        )
+    else:
+        filtered_valid_indices = np.empty((0, 0))
+    return filtered_valid_indices

hoss/exceptions.py

@@ -57,7 +57,7 @@ class InvalidRequestedRange(CustomError):
     def __init__(self):
         super().__init__(
             'InvalidRequestedRange',
-            'Input request specified range outside supported ' 'dimension range',
+            'Input request specified range outside supported dimension range',
         )
 
 
@@ -108,6 +108,79 @@ def __init__(self):
         )
 
 
+class MissingVariable(CustomError):
+    """This exception is raised when HOSS tries to get variables and
+    they are missing or empty.
+
+    """
+
+    def __init__(self, referring_variable):
+        super().__init__(
+            'MissingVariable',
+            f'"{referring_variable}" is ' 'not present in source granule file.',
+        )
+
+
+class MissingCoordinateVariable(CustomError):
+    """This exception is raised when HOSS tries to get latitude and longitude
+    variables and they are missing or empty. These variables are referred to
+    in the science variables with coordinate attributes.
+
+    """
+
+    def __init__(self, referring_variable):
+        super().__init__(
+            'MissingCoordinateVariable',
+            f'Coordinate: "{referring_variable}" is '
+            'not present in source granule file.',
+        )
+
+
+class InvalidCoordinateVariable(CustomError):
+    """This exception is raised when HOSS tries to get latitude and longitude
+    variables and they have fill values to the extent that it cannot be used.
+    These variables are referred in the science variables with coordinate attributes.
+
+    """
+
+    def __init__(self, referring_variable):
+        super().__init__(
+            'InvalidCoordinateVariable',
+            f'Coordinate: "{referring_variable}" is '
+            'not valid in source granule file.',
+        )
+
+
+class IncompatibleCoordinateVariables(CustomError):
+    """This exception is raised when HOSS tries to get latitude and longitude
+    coordinate variable and they do not match in shape or have a size of 0.
+
+    """
+
+    def __init__(self, longitude_shape, latitude_shape):
+        super().__init__(
+            'IncompatibleCoordinateVariables',
+            f'Longitude coordinate shape: "{longitude_shape}"'
+            f'does not match the latitude coordinate shape: "{latitude_shape}"',
+        )
+
+
+class InvalidCoordinateDataset(CustomError):
+    """This exception is raised when the two values passed to
+    the function computing the resolution are equal. This could
+    occur when there are too many fill values and distinct valid
+    indices could not be obtained
+
+    """
+
+    def __init__(self, dim_value, dim_index):
+        super().__init__(
+            'InvalidCoordinateDataset',
+            'Cannot compute the dimension resolution for '
+            f'dim_value: "{dim_value}" dim_index: "{dim_index}"',
+        )
+
+
 class UnsupportedShapeFileFormat(CustomError):
     """This exception is raised when the shape file included in the input
     Harmony message is not GeoJSON.