openavmkit.utilities.geometry

clean_geometry

clean_geometry(gdf, ensure_polygon=True, target_crs=None)

Preprocess a GeoDataFrame by diagnosing and fixing common geometry issues.

Parameters:

Name	Type	Description	Default
gdf	GeoDataFrame	The input GeoDataFrame with geometries.	required
ensure_polygon	bool	If True, removes non-polygon geometries.	True
target_crs	str | int	If specified, ensures the GeoDataFrame is in this CRS.	None

Returns:

Type	Description
GeoDataFrame	A cleaned and fixed GeoDataFrame.

Source code in openavmkit/utilities/geometry.py

def clean_geometry(gdf, ensure_polygon=True, target_crs=None):
    """Preprocess a GeoDataFrame by diagnosing and fixing common geometry issues.

    Parameters
    ----------
    gdf : GeoDataFrame
        The input GeoDataFrame with geometries.
    ensure_polygon : bool
        If True, removes non-polygon geometries.
    target_crs : str | int, optional
        If specified, ensures the GeoDataFrame is in this CRS.

    Returns
    -------
    gpd.GeoDataFrame
        A cleaned and fixed GeoDataFrame.
    """

    # Drop null geometries
    warnings.filterwarnings("ignore", "GeoSeries.notna", UserWarning)
    gdf = gdf[gdf.geometry.notna()]
    warnings.filterwarnings("default", "GeoSeries.notna", UserWarning)

    # Fix invalid geometries using buffer(0)
    gdf["geometry"] = gdf["geometry"].apply(
        lambda geom: geom.buffer(0) if not geom.is_valid else geom
    )

    # Remove empty geometries
    gdf = gdf[~gdf.is_empty]

    # Ensure all polygons are properly closed (for Polygons and MultiPolygons)
    def close_polygon(geom):
        if isinstance(geom, Polygon):
            if not geom.exterior.is_closed:
                return Polygon(list(geom.exterior.coords) + [geom.exterior.coords[0]])
        return geom

    gdf["geometry"] = gdf["geometry"].apply(close_polygon)

    # Remove geometries with fewer than 4 points (invalid for polygons)
    def valid_polygon(geom):
        if isinstance(geom, Polygon):
            return len(geom.exterior.coords) >= 4
        elif isinstance(geom, MultiPolygon):
            for poly in list(geom.geoms):
                if len(poly.exterior.coords) < 4:
                    return False
            return True
        return False

    gdf = gdf[gdf.geometry.apply(valid_polygon)]

    # Remove non-polygon geometries if ensure_polygon is True
    if ensure_polygon:
        gdf = gdf[gdf.geometry.type.isin(["Polygon", "MultiPolygon"])]

    # Ensure the CRS is consistent
    if target_crs:
        gdf = gdf.to_crs(target_crs)

    return gdf

create_geo_circle

create_geo_circle(lat, lon, crs, radius_km, num_points=100)

Creates a GeoDataFrame containing a circle centered at the specified latitude and longitude.

Parameters:

Name	Type	Description	Default
lat	float	Latitude	required
lon	float	Longitude	required
crs	CRS	Coordinate Reference System	required
radius_km	float	Radius of the circle, in kilometers	required
num_points	int	Number of points used to approximate the circle	100

Returns:

Type	Description
GeoDataFrame	A GeoDataFrame containing the circle

Source code in openavmkit/utilities/geometry.py

def create_geo_circle(lat, lon, crs, radius_km, num_points=100):
    """Creates a GeoDataFrame containing a circle centered at the specified latitude and
    longitude.

    Parameters
    ----------
    lat : float
        Latitude
    lon : float
        Longitude
    crs : CRS
        Coordinate Reference System
    radius_km : float
        Radius of the circle, in kilometers
    num_points : int
        Number of points used to approximate the circle

    Returns
    -------
    gpd.GeoDataFrame
        A GeoDataFrame containing the circle
    """
    # Create a list of points around the circle
    points = []
    for i in range(num_points):
        angle = 2 * 3.14159 * i / num_points
        x = radius_km * math.cos(angle)
        y = radius_km * math.sin(angle)
        pt_lat, pt_lon = offset_coordinate_km(lat, lon, x, y)
        points.append(shapely.Point(pt_lon, pt_lat))

    points.append(points[0])
    polygon = shapely.Polygon(points)

    # Create a GeoDataFrame from the points
    gdf = gpd.GeoDataFrame(geometry=[polygon], crs=crs)
    return gdf

create_geo_rect

create_geo_rect(lat, lon, crs, width_km, height_km, anchor_point='center')

Creates a GeoDataFrame containing a rectangle centered at the specified latitude and longitude.

Parameters:

Name	Type	Description	Default
lat	float	Latitude	required
lon	float	Longitude	required
crs	CRS	Coordinate Reference System	required
width_km	float	Width in kilometers	required
height_km	float	Height in kilometers	required
anchor_point	str	Anchor point of the rectangle ("center", "nw")	'center'

Returns:

Type	Description
GeoDataFrame	A GeoDataFrame containing the rectangle.

Source code in openavmkit/utilities/geometry.py

def create_geo_rect(lat, lon, crs, width_km, height_km, anchor_point="center"):
    """Creates a GeoDataFrame containing a rectangle centered at the specified latitude
    and longitude.

    Parameters
    ----------
    lat : float
        Latitude
    lon : float
        Longitude
    crs : CRS
        Coordinate Reference System
    width_km : float
        Width in kilometers
    height_km : float
        Height in kilometers
    anchor_point : str, optional
        Anchor point of the rectangle ("center", "nw")

    Returns
    -------
    gpd.GeoDataFrame
        A GeoDataFrame containing the rectangle.
    """

    polygon = create_geo_rect_shape_km(
        lat, lon, width_km, height_km, anchor_point=anchor_point
    )

    # Create a GeoDataFrame
    gdf = gpd.GeoDataFrame(geometry=[polygon], crs=crs)

    return gdf

create_geo_rect_shape_deg

create_geo_rect_shape_deg(lat, lon, width_deg, height_deg, anchor_point='center')

Creates a GeoDataFrame containing a rectangle centered at the specified latitude and longitude.

Parameters:

Name	Type	Description	Default
lat	float	Latitude	required
lon	float	Longitude	required
height_deg	float	The height of the rectangle in degrees	required
width_deg	float	The height of the rectangle in degrees	required
anchor_point	str	The anchor point of the rectangle ("center" or "nw")	'center'

Returns:

Type	Description
GeoDataFrame	A GeoDataFrame containing the rectangle.

Source code in openavmkit/utilities/geometry.py

def create_geo_rect_shape_deg(lat, lon, width_deg, height_deg, anchor_point="center"):
    """Creates a GeoDataFrame containing a rectangle centered at the specified latitude
    and longitude.

    Parameters
    ----------
    lat : float
        Latitude
    lon : float
        Longitude
    height_deg : float
        The height of the rectangle in degrees
    width_deg : float
        The height of the rectangle in degrees
    anchor_point : str
        The anchor point of the rectangle ("center" or "nw")

    Returns
    -------
    gpd.GeoDataFrame
        A GeoDataFrame containing the rectangle.
    """

    if anchor_point == "center":
        off_nw_x = -width_deg / 2
        off_sw_x = -width_deg / 2

        off_ne_x = width_deg / 2
        off_se_x = width_deg / 2

        off_nw_y = height_deg / 2
        off_ne_y = height_deg / 2

        off_se_y = -height_deg / 2
        off_sw_y = -height_deg / 2
    elif anchor_point == "nw":
        off_nw_x = 0
        off_sw_x = 0

        off_ne_x = width_deg
        off_se_x = width_deg

        off_nw_y = 0
        off_ne_y = 0

        off_se_y = -height_deg
        off_sw_y = -height_deg
    else:
        raise ValueError("Invalid anchor point. Choose 'center' or 'nw'.")

    # Calculate the four corners of the rectangle
    nw_lat, nw_lon = lat + off_nw_y, lon + off_nw_x  # NW
    ne_lat, ne_lon = lat + off_ne_y, lon + off_ne_x  # NE
    se_lat, se_lon = lat + off_se_y, lon + off_se_x  # SE
    sw_lat, sw_lon = lat + off_sw_y, lon + off_sw_x  # SW

    # Order: NW → NE → SE → SW → NW (to close polygon)
    polygon_coords = [
        (nw_lon, nw_lat),
        (ne_lon, ne_lat),
        (se_lon, se_lat),
        (sw_lon, sw_lat),
        (nw_lon, nw_lat),
    ]

    # Create a Polygon
    polygon = Polygon(polygon_coords)
    return polygon

create_geo_rect_shape_km

create_geo_rect_shape_km(lat, lon, width_km, height_km, anchor_point='center')

Creates a GeoDataFrame containing a rectangle centered at the specified latitude and longitude.

Parameters:

Name	Type	Description	Default
lat	float	Latitude	required
lon	float	Longitude	required
width_km	float	Width of the rectangle in kilometers	required
height_km	float	Height of the rectangle in kilometers	required
anchor_point	str	Anchor point of the rectangle ("center", "now")	'center'

Returns:

Type	Description
GeoDataFrame	A GeoDataFrame containing the rectangle.

Source code in openavmkit/utilities/geometry.py

def create_geo_rect_shape_km(lat, lon, width_km, height_km, anchor_point="center"):
    """Creates a GeoDataFrame containing a rectangle centered at the specified latitude
    and longitude.

    Parameters
    ----------
    lat : float
        Latitude
    lon : float
        Longitude
    width_km : float
        Width of the rectangle in kilometers
    height_km : float
        Height of the rectangle in kilometers
    anchor_point : str
        Anchor point of the rectangle ("center", "now")

    Returns
    -------
    gpd.GeoDataFrame
        A GeoDataFrame containing the rectangle.
    """

    if anchor_point == "center":
        off_nw_x = -width_km / 2
        off_sw_x = -width_km / 2

        off_ne_x = width_km / 2
        off_se_x = width_km / 2

        off_nw_y = height_km / 2
        off_ne_y = height_km / 2

        off_se_y = -height_km / 2
        off_sw_y = -height_km / 2
    elif anchor_point == "nw":
        off_nw_x = 0
        off_sw_x = 0

        off_ne_x = width_km
        off_se_x = width_km

        off_nw_y = 0
        off_ne_y = 0

        off_se_y = -height_km
        off_sw_y = -height_km
    else:
        raise ValueError("Invalid anchor point. Choose 'center' or 'nw'.")

    # Calculate the four corners of the rectangle
    nw_lat, nw_lon = offset_coordinate_km(lat, lon, off_nw_y, off_nw_x)  # NW
    ne_lat, ne_lon = offset_coordinate_km(lat, lon, off_ne_y, off_ne_x)  # NE
    se_lat, se_lon = offset_coordinate_km(lat, lon, off_se_y, off_se_x)  # SE
    sw_lat, sw_lon = offset_coordinate_km(lat, lon, off_sw_y, off_sw_x)  # SW

    # Order: NW → NE → SE → SW → NW (to close polygon)
    polygon_coords = [
        (nw_lon, nw_lat),
        (ne_lon, ne_lat),
        (se_lon, se_lat),
        (sw_lon, sw_lat),
        (nw_lon, nw_lat),
    ]

    # Create a Polygon
    polygon = Polygon(polygon_coords)
    return polygon

detect_triangular_lots

detect_triangular_lots(geom, compactness_threshold=0.85, angle_tolerance=10, min_aspect=0.5, max_aspect=2.0)

Determine if a geometry is approximately triangular based on compactness, hull vertex angles, and bounding box aspect ratio.

This function evaluates a shape by:

1. Computing the ratio of its area to its convex hull area (compactness).
2. Checking that the convex hull has at most three non-nearly-180° angles within the specified tolerance, indicating a triangle-like hull.
3. Verifying the bounding box aspect ratio is within [min_aspect, max_aspect].

Parameters:

Name	Type	Description	Default
geom	BaseGeometry	Input polygonal geometry to test (must have an 'area' and 'convex_hull').	required
compactness_threshold	float	Minimum allowed ratio of geom.area to its convex_hull.area. Shapes with more concave boundaries (lower ratios) are rejected.	0.85
angle_tolerance	float	Degrees of tolerance from 180° for hull vertex angles.	10
min_aspect	float	Minimum width/height ratio of the geometry's bounding box.	0.5
max_aspect	float	Maximum width/height ratio of the geometry's bounding box.	2.0

Returns:

Type	Description
bool	True if geom passes all triangularity checks; False otherwise.

Source code in openavmkit/utilities/geometry.py

def detect_triangular_lots(
    geom, compactness_threshold=0.85, angle_tolerance=10, min_aspect=0.5, max_aspect=2.0
):
    """
    Determine if a geometry is approximately triangular based on compactness,
    hull vertex angles, and bounding box aspect ratio.

    This function evaluates a shape by:

    1. Computing the ratio of its area to its convex hull area (compactness).
    2. Checking that the convex hull has at most three non-nearly-180° angles within
       the specified tolerance, indicating a triangle-like hull.
    3. Verifying the bounding box aspect ratio is within [min_aspect, max_aspect].

    Parameters
    ----------
    geom : shapely.geometry.base.BaseGeometry
        Input polygonal geometry to test (must have an 'area' and 'convex_hull').
    compactness_threshold : float, default 0.85
        Minimum allowed ratio of geom.area to its convex_hull.area.
        Shapes with more concave boundaries (lower ratios) are rejected.
    angle_tolerance : float, default 10
        Degrees of tolerance from 180° for hull vertex angles.
    min_aspect : float, default 0.5
        Minimum width/height ratio of the geometry's bounding box.
    max_aspect : float, default 2.0
        Maximum width/height ratio of the geometry's bounding box.

    Returns
    -------
    bool
        True if geom passes all triangularity checks; False otherwise.

    """
    hull = geom.convex_hull
    area_ratio = geom.area / hull.area
    if area_ratio < compactness_threshold:
        return False

    # Check approximate triangular shape
    coords = list(hull.exterior.coords[:-1])
    edges = [
        LineString([coords[i], coords[(i + 1) % len(coords)]])
        for i in range(len(coords))
    ]

    # Calculate angles
    def edge_angle(edge1, edge2):
        vec1 = np.array(edge1.coords[1]) - np.array(edge1.coords[0])
        vec2 = np.array(edge2.coords[1]) - np.array(edge2.coords[0])
        angle = np.arctan2(np.cross(vec1, vec2), np.dot(vec1, vec2))
        return np.degrees(abs(angle))

    angles = [
        edge_angle(edges[i], edges[(i + 1) % len(edges)]) for i in range(len(edges))
    ]
    near_180 = sum(abs(180 - angle) < angle_tolerance for angle in angles)
    if len(edges) - near_180 > 3:
        return False

    # Check bounding box aspect ratio
    bounds = geom.bounds
    width = bounds[2] - bounds[0]
    height = bounds[3] - bounds[1]
    aspect_ratio = width / height
    if not (min_aspect <= aspect_ratio <= max_aspect):
        return False

    return True

distance_km

distance_km(lat1, lon1, lat2, lon2)

Calculates the distance in kilometers between two latitude/longitude points. :param lat1: Latitude of the first point. :param lon1: Longitude of the first point. :param lat2: Latitude of the second point. :param lon2: Longitude of the second point. :return: Distance in kilometers.

Source code in openavmkit/utilities/geometry.py

def distance_km(lat1, lon1, lat2, lon2):
  """
  Calculates the distance in kilometers between two latitude/longitude points.
  :param lat1: Latitude of the first point.
  :param lon1: Longitude of the first point.
  :param lat2: Latitude of the second point.
  :param lon2: Longitude of the second point.
  :return: Distance in kilometers.
  """
  _, _, dist_m = geod.inv(lon1, lat1, lon2, lat2)
  return dist_m / 1000.0

ensure_geometries

ensure_geometries(df, geom_col='geometry', crs=None)

Parse a DataFrame whose geom_col may be:

• Shapely geometries
• WKT strings
• WKB bytes/bytearray
• Hex‐encoded WKB strings (with or without "0x" prefix)
• numpy.bytes_ scalars, memoryviews, etc.

Parameters:

Name	Type	Description	Default
df	DataFrame	Input DataFrame	required
geom_col	str	name of the geometry column	'geometry'
crs	CRS	Coordinate Reference System	None

Returns:

Type	Description
GeoDataFrame	a brand‑new GeoDataFrame with a clean geometry column.

Source code in openavmkit/utilities/geometry.py

def ensure_geometries(df, geom_col="geometry", crs=None):
    """Parse a DataFrame whose `geom_col` may be:

      - Shapely geometries
      - WKT strings
      - WKB bytes/bytearray
      - Hex‐encoded WKB strings (with or without "0x" prefix)
      - numpy.bytes_ scalars, memoryviews, etc.

    Parameters
    ----------
    df : pd.DataFrame
        Input DataFrame
    geom_col : str
        name of the geometry column
    crs : CRS, optional
        Coordinate Reference System

    Returns
    -------
    gpd.GeoDataFrame
        a brand‑new GeoDataFrame with a _clean_ geometry column.
    """
    # Copy into a plain DataFrame (drops any old GeoDataFrame metadata)
    data = pd.DataFrame(df).copy()

    def _parse(val):
        # 1) Nulls
        if val is None or (isinstance(val, float) and pd.isna(val)):
            return None
        # 2) Already Shapely?
        if isinstance(val, BaseGeometry):
            return val
        # 3) Geo‑interface dicts
        if hasattr(val, "__geo_interface__"):
            from shapely.geometry import shape

            return shape(val)
        # 4) Strings: try WKT first, then hex WKB
        if isinstance(val, str):
            s = val.strip()
            if s.lower().startswith("0x"):
                s = s[2:]
            try:
                return wkt.loads(val)
            except Exception:
                raw = binascii.unhexlify(s)
                return wkb.loads(raw)
        # 5) Bytes‐like
        if isinstance(val, (bytes, bytearray, memoryview)):
            raw = val.tobytes() if isinstance(val, memoryview) else val
            return wkb.loads(raw)
        # 6) numpy bytes_ or other numpy scalar
        if isinstance(val, np.generic):
            try:
                b = bytes(val)
                return wkb.loads(b)
            except Exception:
                pass
        # 7) Anything with tobytes()
        if hasattr(val, "tobytes"):
            try:
                raw = val.tobytes()
                return wkb.loads(raw)
            except Exception:
                pass

        raise TypeError(f"Cannot parse geometry of type {type(val)}")

    # Parse into a plain pandas Series of Shapely objects
    parsed = data[geom_col].apply(_parse)

    # Build a GeoSeries (so GeoPandas trusts it)
    geom_series = gpd.GeoSeries(parsed.values.tolist(), index=data.index, crs=crs)

    # Drop the old column and assemble
    df_clean = data.drop(columns=[geom_col])
    return gpd.GeoDataFrame(df_clean, geometry=geom_series, crs=crs)

geolocate_point_to_polygon

geolocate_point_to_polygon(gdf, df_in, lat_field, lon_field, parcel_id_field)

Assign each point (latitude/longitude) in a DataFrame to a containing polygon ID.

Converts input latitude/longitude columns into Point geometries, performs a spatial join against a GeoDataFrame of parcel polygons, and returns the original DataFrame augmented with the matching parcel identifier.

Parameters:

Name	Type	Description	Default
gdf	GeoDataFrame	GeoDataFrame of polygon geometries. Must include: A geometry column of type Polygon or MultiPolygon. The column named by parcel_id_field containing unique parcel IDs.	required
df_in	DataFrame	Input DataFrame with at least the latitude and longitude columns. Any existing geometry column will be dropped.	required
lat_field	str	Name of the column in df_in containing latitude values.	required
lon_field	str	Name of the column in df_in containing longitude values.	required
parcel_id_field	str	Name of the parcel ID column in gdf to attach to each point.	required

Returns:

Type	Description
DataFrame	Copy of df_in with: Any preexisting geometry column removed. A new column parcel_id_field containing the ID of the polygon in gdf that contains each point. Rows with no containing polygon will have NaN.

Notes

• Input DataFrame is temporarily converted to a GeoDataFrame with Point geometries; its CRS is set to match gdf.
• Spatial join uses the 'within' predicate to ensure points fall inside parcels.
• A temporary index column is used to preserve original row order.

Source code in openavmkit/utilities/geometry.py

def geolocate_point_to_polygon(
    gdf: gpd.GeoDataFrame,
    df_in: pd.DataFrame,
    lat_field: str,
    lon_field: str,
    parcel_id_field: str,
) -> pd.DataFrame:
    """
    Assign each point (latitude/longitude) in a DataFrame to a containing polygon ID.

    Converts input latitude/longitude columns into Point geometries, performs a
    spatial join against a GeoDataFrame of parcel polygons, and returns the
    original DataFrame augmented with the matching parcel identifier.

    Parameters
    ----------
    gdf : geopandas.GeoDataFrame
        GeoDataFrame of polygon geometries.  Must include:

        - A geometry column of type Polygon or MultiPolygon.
        - The column named by `parcel_id_field` containing unique parcel IDs.
    df_in : pandas.DataFrame
        Input DataFrame with at least the latitude and longitude columns.
        Any existing `geometry` column will be dropped.
    lat_field : str
        Name of the column in `df_in` containing latitude values.
    lon_field : str
        Name of the column in `df_in` containing longitude values.
    parcel_id_field : str
        Name of the parcel ID column in `gdf` to attach to each point.

    Returns
    -------
    pandas.DataFrame
        Copy of `df_in` with:

        - Any preexisting `geometry` column removed.
        - A new column `parcel_id_field` containing the ID of the polygon in `gdf`
          that contains each point.  Rows with no containing polygon will have NaN.

    Notes
    -----
    - Input DataFrame is temporarily converted to a GeoDataFrame with Point
      geometries; its CRS is set to match `gdf`.
    - Spatial join uses the 'within' predicate to ensure points fall inside
      parcels.
    - A temporary index column is used to preserve original row order.
    """
    # Make a local copy
    df = df_in.copy()

    if "geometry" in df.columns:
        warnings.warn(
            "You're doing a `lat_lon` merge of a DataFrame that also has a `geometry` column. The geometry column will be discarded."
        )

    # Drop fields that don't have lat/lon values
    df = df[df[lon_field].notna() & df[lat_field].notna()]

    # Strip old geometry if it exists and replace it with points corresponding to lat/lon fields
    df = df.drop(columns="geometry", errors="ignore")
    df["geometry"] = df.apply(
        lambda row: shapely.geometry.Point(row[lon_field], row[lat_field]), axis=1
    )
    df = gpd.GeoDataFrame(df, geometry="geometry")

    # Match the CRS
    df.set_crs(gdf.crs, inplace=True)

    # reset index and set a "temp_index" of numerical index values
    df.reset_index(drop=True)
    df["temp_index"] = df.index

    gdf_keys = gdf[[parcel_id_field, "geometry"]]

    # deduplicate:
    gdf_keys = gdf_keys.drop_duplicates(subset=[parcel_id_field])

    # perform the spatial join, each lat/lon matched to the parcel it's inside of
    gdf_joined = gpd.sjoin(df, gdf_keys, how="left", predicate="within")

    # now we have a DataFrame that matches each row in df_in to a `parcel_id_field` in gdf

    # merge parcel_id_field back onto df:
    df = df.merge(
        gdf_joined[[parcel_id_field, "temp_index"]], on="temp_index", how="left"
    )

    # drop the temporary index and the point geometry:
    df = df.drop(columns=["temp_index", "geometry"])

    # now df has the parcel_id_field for each lat/lon pair in gdf

    return df

get_crs

get_crs(gdf, projection_type)

Returns the appropriate CRS for a GeoDataFrame based on the specified projection type.

Parameters:

Name	Type	Description	Default
gdf	GeoDataFrame	Input GeoDataFrame.	required
projection_type	str	Type of projection ('latlon', 'equal_area', 'equal_distance').	required

Returns:

Type	Description
CRS	Appropriate CRS for the specified projection type.

Source code in openavmkit/utilities/geometry.py

def get_crs(gdf, projection_type):
    """Returns the appropriate CRS for a GeoDataFrame based on the specified projection
    type.

    Parameters
    ----------
    gdf : gpd.GeoDataFrame
        Input GeoDataFrame.
    projection_type : str
        Type of projection ('latlon', 'equal_area', 'equal_distance').

    Returns
    -------
    pyproj.CRS
        Appropriate CRS for the specified projection type.
    """
    # Ensure the GeoDataFrame is in EPSG:4326
    gdf = gdf.to_crs("EPSG:4326")

    # Calculate the centroid of the entire GeoDataFrame

    # supress user warning:
    warnings.filterwarnings("ignore", category=UserWarning)

    # get centroid:
    lon, lat = gdf.centroid.x.mean(), gdf.centroid.y.mean()

    return get_crs_from_lat_lon(lat, lon, projection_type)

get_crs_from_lat_lon

get_crs_from_lat_lon(lat, lon, projection_type, units='m')

Return a Coordinate Reference System (CRS) suitable for the requested projection type at the given latitude/longitude location.

Parameters:

Name	Type	Description	Default
lat	float	Latitude	required
lon	float	Longitude	required
projection_type	str	The desired projection type. Legal values are "latlon", "equal_area", "equal_distance", and "conformal"	required
units	str	The desired units. Legal values are "ft" and "m"	'm'

Returns:

Type	Description
CRS	The appropriately Coordinate Reference System

Notes

The following kind of CRS will be returned for each of the projection_type values:

• 'latlon' : geographic (EPSG:4326)
• 'equal_area' : local azimuthal equal-area (LAEA)
• 'equal_distance': azimuthal equidistant (AEQD)
• 'conformal' : local UTM zone (minimal distortion in shape/angle)

Source code in openavmkit/utilities/geometry.py

def get_crs_from_lat_lon(
    lat: float, lon: float, projection_type: str, units: str = "m"
):
    """Return a Coordinate Reference System (CRS) suitable for the requested projection type at the given
    latitude/longitude location.

    Parameters
    ----------
    lat : float
        Latitude
    lon : float
        Longitude
    projection_type : str
        The desired projection type. Legal values are "latlon", "equal_area", "equal_distance", and "conformal"
    units : str
        The desired units. Legal values are "ft" and "m"

    Returns
    -------
    CRS
        The appropriately Coordinate Reference System

    Notes
    -----
    The following kind of CRS will be returned for each of the ``projection_type`` values:

      - 'latlon'       : geographic (EPSG:4326)
      - 'equal_area'   : local azimuthal equal-area (LAEA)
      - 'equal_distance': azimuthal equidistant (AEQD)
      - 'conformal'    : local UTM zone (minimal distortion in shape/angle)
    """
    if projection_type == "latlon":
        return CRS.from_epsg(4326)

    elif projection_type == "equal_area":
        # Lambert Azimuthal Equal‐Area about your centroid
        return CRS.from_proj4(
            f"+proj=laea +lat_0={lat} +lon_0={lon} +datum=WGS84 +units={units}"
        )

    elif projection_type == "equal_distance":
        # Azimuthal Equidistant about your centroid
        return CRS.from_proj4(
            f"+proj=aeqd +lat_0={lat} +lon_0={lon} +datum=WGS84 +units={units}"
        )

    elif projection_type == "conformal":
        # Use the UTM zone for minimal scale error over a small area
        # pyproj can detect the right UTM zone automatically:
        return CRS.from_user_input(
            f"+proj=utm +zone={int((lon+180)/6)+1} +datum=WGS84 +units={units}"
        )

    else:
        raise ValueError(f"Unknown projection_type: {projection_type}")

get_exterior_coords

get_exterior_coords(geom)

Gets a list of all the exterior coordinates, regardless of whether the Geometry is a Polygon or MultiPolygon

Parameters:

Name	Type	Description	Default
geom	Polygon	The shapely polygon whose exterior coordinates you want	required

Returns:

Type	Description
list	The list of exterior coordinates

Source code in openavmkit/utilities/geometry.py

def get_exterior_coords(geom):
    """Gets a list of all the exterior coordinates, regardless of whether the Geometry is a Polygon or MultiPolygon

    Parameters
    ----------
    geom : shapely.Polygon
        The shapely polygon whose exterior coordinates you want

    Returns
    -------
    list
        The list of exterior coordinates
    """
    if geom.geom_type == "Polygon":
        return list(geom.exterior.coords)
    elif geom.geom_type == "MultiPolygon":
        # Return a list of exterior coordinates for each polygon in the MultiPolygon
        return [list(poly.exterior.coords) for poly in geom.geoms]
    else:
        return None  # or handle other geometry types if necessary

identify_irregular_parcels

identify_irregular_parcels(gdf, verbose=False, tolerance=10, complex_threshold=12, rectangularity_threshold=0.75, elongation_threshold=5)

Detect and flag irregular parcel geometries based on shape metrics.

Applies a sequence of geometric tests to identify triangular, overly complex, or elongated parcel shapes. The input GeoDataFrame is temporarily projected to EPSG:3857 for distance-based operations, then restored to its original CRS.

Parameters:

Name	Type	Description	Default
gdf	GeoDataFrame	Must contain a geometry column of Polygon geometries, plus precomputed fields: geom_rectangularity_num : numeric rectangularity measure (0–1). geom_aspect_ratio : width/height ratio of each parcel.	required
verbose	bool	If True, print timing and progress for each processing phase.	False
tolerance	int	Simplification tolerance (projection units) for reducing geometry complexity before analysis.	10
complex_threshold	int	Minimum vertex count (post-simplification) for a parcel to be considered 'complex' when rectangularity is low.	12
rectangularity_threshold	float	Maximum rectangularity below which a high-vertex-count geometry is flagged as irregular.	0.75
elongation_threshold	float	Minimum bounding-box aspect ratio that qualifies a parcel as 'elongated'.	5

Returns:

Type	Description
GeoDataFrame	A copy of the input with these added columns: is_geom_triangular : bool flag for approximate triangular shapes. geom_vertices : int count of vertices after simplification. is_geom_complex : bool flag for complex non-rectangular shapes. is_geom_elongated : bool flag for elongated shapes. is_geom_irregular : bool flag if any irregular condition is met.

Notes

• The original CRS is preserved in the final output.
• Triangle detection delegates to :func:detect_triangular_lots.
• Complex shapes satisfy both: vertex count ≥ complex_threshold AND rectangularity ≤ rectangularity_threshold.
• Elongation is evaluated on the axis-aligned bounding box of each parcel.

Source code in openavmkit/utilities/geometry.py

def identify_irregular_parcels(
    gdf,
    verbose=False,
    tolerance=10,
    complex_threshold=12,
    rectangularity_threshold=0.75,
    elongation_threshold=5,
):
    """
    Detect and flag irregular parcel geometries based on shape metrics.

    Applies a sequence of geometric tests to identify triangular, overly
    complex, or elongated parcel shapes.  The input GeoDataFrame is temporarily
    projected to EPSG:3857 for distance-based operations, then restored to its
    original CRS.

    Parameters
    ----------
    gdf : geopandas.GeoDataFrame
        Must contain a ``geometry`` column of Polygon geometries, plus
        precomputed fields:

        - ``geom_rectangularity_num`` : numeric rectangularity measure (0–1).
        - ``geom_aspect_ratio``     : width/height ratio of each parcel.
    verbose : bool, default False
        If True, print timing and progress for each processing phase.
    tolerance : int, default 10
        Simplification tolerance (projection units) for reducing geometry
        complexity before analysis.
    complex_threshold : int, default 12
        Minimum vertex count (post-simplification) for a parcel to be
        considered 'complex' when rectangularity is low.
    rectangularity_threshold : float, default 0.75
        Maximum rectangularity below which a high-vertex-count geometry is
        flagged as irregular.
    elongation_threshold : float, default 5
        Minimum bounding-box aspect ratio that qualifies a parcel as
        'elongated'.

    Returns
    -------
    geopandas.GeoDataFrame
        A copy of the input with these added columns:

        - ``is_geom_triangular`` : bool flag for approximate triangular shapes.
        - ``geom_vertices``      : int count of vertices after simplification.
        - ``is_geom_complex``    : bool flag for complex non-rectangular shapes.
        - ``is_geom_elongated``  : bool flag for elongated shapes.
        - ``is_geom_irregular``  : bool flag if any irregular condition is met.

    Notes
    -----
    - The original CRS is preserved in the final output.
    - Triangle detection delegates to :func:`detect_triangular_lots`.
    - Complex shapes satisfy both: vertex count ≥ ``complex_threshold`` AND
      rectangularity ≤ ``rectangularity_threshold``.
    - Elongation is evaluated on the axis-aligned bounding box of each parcel.
    """
    if verbose:
        print(f"--> identifying irregular parcels...")

    t = TimingData()
    t.start("all")
    t.start("setup")
    old_crs = gdf.crs
    if gdf.crs.is_geographic:
        gdf = gdf.to_crs("EPSG:3857")
    gdf["simplified_geometry"] = gdf.geometry.simplify(
        tolerance, preserve_topology=True
    )
    t.stop("setup")

    t.start("tri")
    gdf["is_geom_triangular"] = gdf["simplified_geometry"].apply(detect_triangular_lots)
    t.stop("tri")
    if verbose:
        _t = t.get("setup")
        print(f"----> simplified geometry...({_t:.2f}s)")
        _t = t.get("tri")
        print(f"----> identified triangular parcels...({_t:.2f}s)")

    # Detect complex geometry based on rectangularity and vertex count
    t.start("complex")
    gdf["geom_vertices"] = gdf["simplified_geometry"].apply(
        lambda geom: len(geom.exterior.coords) if geom.geom_type == "Polygon" else 0
    )
    gdf["is_geom_complex"] = (gdf["geom_vertices"].ge(complex_threshold)) & (
        gdf["geom_rectangularity_num"].le(rectangularity_threshold)
    )
    t.stop("complex")
    if verbose:
        _t = t.get("complex")
        print(f"----> identified complex geometry...({_t:.2f}s)")

    t.start("long")
    gdf["is_geom_elongated"] = gdf["geom_aspect_ratio"].ge(elongation_threshold)
    t.stop("long")
    if verbose:
        _t = t.get("long")
        print(f"----> identified elongated parcels...({_t:.2f}s)")

    t.start("finish")
    # Combine criteria for irregular lots
    gdf["is_geom_irregular"] = (
        gdf["is_geom_complex"] | gdf["is_geom_elongated"] | gdf["is_geom_triangular"]
    )

    # Fill any NA values with false:
    for field in [
        "is_geom_complex",
        "is_geom_elongated",
        "is_geom_triangular",
        "is_geom_irregular",
    ]:
        gdf[field] = gdf[field].fillna(False)
        gdf[field] = gdf[field].astype(bool)

    gdf = gdf.drop(columns="simplified_geometry")
    gdf = gdf.to_crs(old_crs)
    t.stop("finish")
    if verbose:
        _t = t.get("finish")
        print(f"----> finished up...({_t:.2f}s)")
    t.stop("all")
    if verbose:
        _t = t.get("all")
        print(f"--> identified irregular parcels (total)...({_t:.2f}s)")

    return gdf

is_likely_epsg4326

is_likely_epsg4326(gdf)

Checks if the GeoDataFrame is likely using EPSG:4326.

This is a heuristic function that inspects the geometries.

Parameters:

Name	Type	Description	Default
gdf	GeoDataFrame	The GeoDataFrame to check	required

Returns:

Type	Description
bool	True if it's likely EPSG:4326, False if it's not.

Source code in openavmkit/utilities/geometry.py

def is_likely_epsg4326(gdf: gpd.GeoDataFrame) -> bool:
    """Checks if the GeoDataFrame is likely using EPSG:4326.

    This is a heuristic function that inspects the geometries.

    Parameters
    ----------
    gdf : gpd.GeoDataFrame
        The GeoDataFrame to check

    Returns
    -------
    bool
        True if it's likely EPSG:4326, False if it's not.

    """
    # Check if geometries have lat/lon coordinates within typical ranges
    for geom in gdf.geometry.head(10):  # Check first 10 geometries for efficiency
        if geom.is_empty:
            continue
        if not geom.bounds:
            continue
        min_x, min_y, max_x, max_y = geom.bounds
        # Longitude range: -180 to 180, Latitude range: -90 to 90
        if not (-180 <= min_x <= 180 and -180 <= max_x <= 180):
            return False
        if not (-90 <= min_y <= 90 and -90 <= max_y <= 90):
            return False
    return True

offset_coordinate_feet

offset_coordinate_feet(lat, lon, lat_feet, lon_feet)

Offset a lat/long coordinate by the designated number of feet

Parameters:

Name	Type	Description	Default
lat	float	Latitude	required
lon	float	Longitude	required
lat_feet	float	Number of feet to offset latitude by	required
lon_feet	float	Number of feet to offset longitude by	required

Returns:

Type	Description
tuple[float, float]	The offset latitude, longitude pair (in degrees)

Source code in openavmkit/utilities/geometry.py

def offset_coordinate_feet(lat, lon, lat_feet, lon_feet) -> (float, float):
    """Offset a lat/long coordinate by the designated number of feet

    Parameters
    ----------
    lat : float
        Latitude
    lon : float
        Longitude
    lat_feet : float
        Number of feet to offset latitude by
    lon_feet : float
        Number of feet to offset longitude by

    Returns
    -------
    tuple[float, float]
        The offset latitude, longitude pair (in degrees)
    """
    lat_km = lat_feet * 0.0003048
    lon_km = lon_feet * 0.0003048
    return offset_coordinate_km(lat, lon, lat_km, lon_km)

offset_coordinate_m

offset_coordinate_m(lat, lon, lat_m, lon_m)

Offset a lat/long coordinate by the designated number of meters

Parameters:

Name	Type	Description	Default
lat	float	Latitude	required
lon	float	Longitude	required
lat_m	float	Number of meters to offset latitude by	required
lon_m	float	Number of meters to offset longitude by	required

Returns:

Type	Description
tuple[float, float]	The offset latitude, longitude pair (in degrees)

Source code in openavmkit/utilities/geometry.py

def offset_coordinate_m(lat, lon, lat_m, lon_m) -> (float, float):
    """Offset a lat/long coordinate by the designated number of meters

    Parameters
    ----------
    lat : float
        Latitude
    lon : float
        Longitude
    lat_m : float
        Number of meters to offset latitude by
    lon_m : float
        Number of meters to offset longitude by

    Returns
    -------
    tuple[float, float]
        The offset latitude, longitude pair (in degrees)
    """
    lat_km = lat_m / 1000
    lon_km = lon_m / 1000
    return offset_coordinate_km(lat, lon, lat_km, lon_km)

offset_coordinate_miles

offset_coordinate_miles(lat, lon, lat_miles, lon_miles)

Offset a lat/long coordinate by the designated number of miles

Parameters:

Name	Type	Description	Default
lat	float	Latitude	required
lon	float	Longitude	required
lat_miles	float	Number of miles to offset latitude by	required
lon_miles	float	Number of miles to offset longitude by	required

Returns:

Type	Description
tuple[float, float]	The offset latitude, longitude pair (in degrees)

Source code in openavmkit/utilities/geometry.py

def offset_coordinate_miles(lat, lon, lat_miles, lon_miles) -> (float, float):
    """Offset a lat/long coordinate by the designated number of miles

    Parameters
    ----------
    lat : float
        Latitude
    lon : float
        Longitude
    lat_miles : float
        Number of miles to offset latitude by
    lon_miles : float
        Number of miles to offset longitude by

    Returns
    -------
    tuple[float, float]
        The offset latitude, longitude pair (in degrees)
    """
    lat_km = lat_miles * 1.60934
    lon_km = lon_miles * 1.60934
    return offset_coordinate_km(lat, lon, lat_km, lon_km)