Module losanalyst.functions.checks

Functions

def check_los_layer(layer)

Checks that the layer is LoS layer.

Parameters

layer : ogr.Layer

Layer to perform the check on.

Raises

ValueError

If the layer is not LoS.

Expand source code

def check_los_layer(layer: ogr.Layer) -> None:
    """
    Checks that the `layer` is LoS layer.

    Parameters
    ----------
    layer : ogr.Layer
        Layer to perform the check on.

    Raises
    ------
    ValueError
        If the `layer` is not LoS.
    """
    if not is_los_layer(layer):
        raise ValueError("The provided LoS layer does not provide the necessary attributes. "
                         "It cannot be correctly processed.")

def check_return_id_field(layer, layer_name, field_name)

Checks if the provided field (field_name) exists in layer. If it does not or it is not Integer data type outputs warning and sets return value as None.

Parameters

layer : ogr.Layer

Layer to verify.

layer_name : str

Layer name for warning messages.

field_name : str

Name of the field to look for.

Returns

str

Either the name of the field or value None if does not exists or if it is of incorrect type.

Warns

UserWarning

If the field does not exist or if it is not Integer type.

Expand source code

def check_return_id_field(layer: ogr.Layer,
                          layer_name: str,
                          field_name: str) -> str:
    """
    Checks if the provided field (`field_name`) exists in `layer`. If it does not or it is not `Integer` data type
    outputs warning and sets return value as `None`.

    Parameters
    ----------
    layer : ogr.Layer
        Layer to verify.

    layer_name : str
        Layer name for warning messages.

    field_name : str
        Name of the field to look for.

    Returns
    -------
    str
        Either the name of the field or value `None` if does not exists or if it is of incorrect type.

    Warns
    -------
    UserWarning
        If the field does not exist or if it is not Integer type.
    """

    if field_name is not None:
        if not layer_checks.does_field_exist(layer, field_name):
            warnings.warn(
                "The field `{0}` does not exist in `{1}`, the default gdal FID will be used instead."
                    .format(field_name, layer_name),
                UserWarning
            )
            field_name = None
        elif not layer_checks.is_field_of_type(layer, field_name, ogr.OFTInteger):
            warnings.warn(
                "The field `{0}` in observers is not an `Integer` type, the default gdal FID will be used instead."
                    .format(field_name),
                UserWarning
            )
            field_name = None

    return field_name

def check_return_sampling_distance(sampling_distance, dsm)

Checks that the provided sampling distance value is valid one, if it is None then estimates it based on pixel size of dsm.

Parameters

sampling_distance : int or float

Value of LoS sampling distance. Should be positive number.

dsm : DEM

If the sampling_distance is not provided, it is estimated as pixel size of dsm.

Returns

float

Sampling distance.

Expand source code

def check_return_sampling_distance(sampling_distance: Union[int, float], dsm: DEM) -> float:
    """
    Checks that the provided sampling distance value is valid one, if it is `None` then estimates it based on pixel size
    of `dsm`.

    Parameters
    ----------
    sampling_distance : int or float
        Value of LoS sampling distance. Should be positive number.

    dsm : DEM
        If the `sampling_distance` is not provided, it is estimated as pixel size of `dsm`.

    Returns
    -------
    float
        Sampling distance.
    """

    if sampling_distance is not None:
        values_checks.check_value_is_zero_or_positive(sampling_distance, "sampling_distance")
        return float(sampling_distance)
    else:
        sampling_distance = dsm.get_min_pixel_size()
        return sampling_distance

def check_return_set_offset(offset, offset_name, layer, layer_name, default_offset=1.75)

Checks that offset is usable. The offset is either str, which specifies field name in layer from which the value is obtained, or float and int which are used directly.

Parameters

offset : str or int or float

Either numerical value or string specifying field name of layer.

offset_name : str

Name of the offset for warning messages.

layer : ogr.Layer

Layer to work with.

layer_name : str

Name of the layer for warning messages.

default_offset : float, optional

Offset value to use if the field does not exist. Default value is 1.75.

Returns

str or float

Either verified name of the field from layer or numerical value.

Raises

ValueError

If some of the values is not valid.

Warns

UserWarning

If the field does not exist or if it is of non-numerical type.

Expand source code

def check_return_set_offset(offset: Union[str, int, float],
                            offset_name: str,
                            layer: ogr.Layer,
                            layer_name: str,
                            default_offset: float = 1.75):
    """
    Checks that `offset` is usable. The `offset` is either `str`, which specifies field name in `layer` from which the
    value is obtained, or `float` and `int` which are used directly.

    Parameters
    ----------
    offset : str or int or float
        Either numerical value or string specifying field name of `layer`.

    offset_name : str
        Name of the offset for warning messages.

    layer : ogr.Layer
        Layer to work with.

    layer_name : str
        Name of the layer for warning messages.

    default_offset : float, optional
        Offset value to use if the field does not exist. Default value is `1.75`.

    Returns
    -------
    str or float
        Either verified name of the field from `layer` or numerical value.

    Raises
    ------
    ValueError
        If some of the values is not valid.

    Warns
    -------
    UserWarning
        If the field does not exist or if it is of non-numerical type.
    """

    if not isinstance(default_offset, (float, int)):
        raise ValueError("The `default_offset` variable is not either `int` or `float`. It is: `{0}`."
                         .format(type(default_offset).__name__))

    if isinstance(offset, str):
        if not layer_checks.does_field_exist(layer, offset):
            warnings.warn(
                "`{0}` `{1}` does not exist in `{2}` layer, the default value of offset `{3}` will be used."
                    .format(offset_name, offset, layer_name, default_offset),
                UserWarning
            )
            return default_offset

        elif not (layer_checks.is_field_of_type(layer, offset, ogr.OFTInteger) or
                  layer_checks.is_field_of_type(layer, offset, ogr.OFTReal)):
            warnings.warn(
                "`{0}` field `{1}` is not either `Integer` or `Real` in `{2}` layer, "
                "the default value of offset `{3}` will be used."
                    .format(offset_name, offset, layer_name, default_offset),
                UserWarning
            )
            return default_offset
        else:
            return offset

    elif isinstance(offset, (int, float)):
        return offset

    else:
        raise ValueError("The `{0}` is not either string or number.".format(offset_name))

def is_global_los_layer(layer)

Verify that the given layer contain global LoS data.

Parameters

layer : ogr.Layer

Layer to perform the check on.

Returns

bool

 

Expand source code

def is_global_los_layer(layer: ogr.Layer) -> bool:
    """
    Verify that the given `layer` contain global LoS data.

    Parameters
    ----------
    layer : ogr.Layer
        Layer to perform the check on.

    Returns
    -------
    bool
    """
    is_global = helpers.get_los_type(layer) == "global"

    result = layer_checks.does_field_exist(layer, field_names.tp_x_field_name) and \
             layer_checks.does_field_exist(layer, field_names.tp_y_field_name) and \
             is_global

    return result

def is_los_layer(layer)

Verify, based on presence of specific fields, that the given layer contains LoS data.

Parameters

layer : ogr.Layer

Layer to perform the check on.

Returns

bool

 

Expand source code

def is_los_layer(layer: ogr.Layer) -> bool:
    """
    Verify, based on presence of specific fields, that the given `layer` contains LoS data.

    Parameters
    ----------
    layer : ogr.Layer
        Layer to perform the check on.

    Returns
    -------
    bool
    """
    result1 = layer_checks.does_field_exist(layer, field_names.observer_id_field_name) and \
              layer_checks.does_field_exist(layer, field_names.target_id_field_name)
    result2 = layer_checks.does_field_exist(layer, field_names.observer_offset_field_name) and \
              layer_checks.does_field_exist(layer, field_names.target_offset_field_name)
    return result1 and result2

def is_los_without_target(layer)

Verify that the given layer contain LoS without target data.

Parameters

layer : ogr.Layer

Layer to perform the check on.

Returns

bool

 

Expand source code

def is_los_without_target(layer: ogr.Layer) -> bool:
    """
    Verify that the given `layer` contain LoS without target data.

    Parameters
    ----------
    layer : ogr.Layer
        Layer to perform the check on.

    Returns
    -------
    bool
    """
    if helpers.get_los_type(layer) == "without target":
        return True
    else:
        return False