File: C:/Users/fred/anaconda3/Lib/site-packages/hvplot/util.py
"""
Provides utilities to convert data and projections
"""
import sys
from collections.abc import Hashable
from functools import wraps
from packaging.version import Version
from types import FunctionType
import bokeh
import numpy as np
import pandas as pd
import param
import holoviews as hv
try:
import panel as pn
panel_available = True
except ImportError:
panel_available = False
hv_version = Version(hv.__version__)
bokeh_version = Version(bokeh.__version__)
_fugue_ipython = None # To be set to True in tests to mock ipython
def with_hv_extension(func, extension='bokeh', logo=False):
"""If hv.extension is not loaded, load before calling function"""
@wraps(func)
def wrapper(*args, **kwargs):
if extension and not getattr(hv.extension, '_loaded', False):
from . import hvplot_extension
hvplot_extension(extension, logo=logo)
return func(*args, **kwargs)
return wrapper
def get_ipy():
try:
ip = get_ipython() # noqa
except NameError:
ip = None
return ip
def check_crs(crs):
"""
Checks if the crs represents a valid grid, projection or ESPG string.
(Code copied and adapted from https://github.com/fmaussion/salem)
Examples
--------
>>> p = check_crs('epsg:26915 +units=m')
>>> p.srs
'+proj=utm +zone=15 +datum=NAD83 +units=m +no_defs'
>>> p = check_crs('wrong')
>>> p is None
True
Returns
-------
A valid crs if possible, otherwise None.
"""
import pyproj
try:
crs_type = pyproj.crs.CRS
except AttributeError:
class Dummy:
pass
crs_type = Dummy
if isinstance(crs, pyproj.Proj):
out = crs
elif isinstance(crs, crs_type):
out = pyproj.Proj(crs.to_wkt(), preserve_units=True)
elif isinstance(crs, dict) or isinstance(crs, str):
if isinstance(crs, str):
try:
crs = pyproj.CRS.from_wkt(crs)
except RuntimeError:
# quick fix for https://github.com/pyproj4/pyproj/issues/345
crs = crs.replace(' ', '').replace('+', ' +')
try:
out = pyproj.Proj(crs, preserve_units=True)
except RuntimeError:
try:
out = pyproj.Proj(init=crs, preserve_units=True)
except RuntimeError:
out = None
else:
out = None
return out
def proj_is_latlong(proj):
"""Shortcut function because of deprecation."""
try:
return proj.is_latlong()
except AttributeError:
return proj.crs.is_geographic
def proj_to_cartopy(proj):
"""
Converts a pyproj.Proj to a cartopy.crs.Projection
(Code copied from https://github.com/fmaussion/salem)
Parameters
----------
proj: pyproj.Proj
the projection to convert
Returns
-------
a cartopy.crs.Projection object
"""
import cartopy.crs as ccrs
try:
from osgeo import osr
has_gdal = True
except ImportError:
has_gdal = False
input_proj = proj
proj = check_crs(input_proj)
if proj is None:
raise ValueError(f'Invalid proj projection {input_proj!r}')
srs = proj.srs
if has_gdal:
import warnings
with warnings.catch_warnings():
# Avoiding this warning could be done by setting osr.UseExceptions(),
# except there might be a risk to break the code of users leveraging
# GDAL on their side or through other libraries. So we just silence it.
warnings.filterwarnings(
'ignore',
category=FutureWarning,
message=r'Neither osr\.UseExceptions\(\) nor osr\.DontUseExceptions\(\) has '
r'been explicitly called\. In GDAL 4\.0, exceptions will be enabled '
'by default',
)
# this is more robust, as srs could be anything (espg, etc.)
s1 = osr.SpatialReference()
s1.ImportFromProj4(proj.srs)
if s1.ExportToProj4():
srs = s1.ExportToProj4()
km_proj = {
'lon_0': 'central_longitude',
'lat_0': 'central_latitude',
'x_0': 'false_easting',
'y_0': 'false_northing',
'lat_ts': 'latitude_true_scale',
'o_lon_p': 'central_rotated_longitude',
'o_lat_p': 'pole_latitude',
'k': 'scale_factor',
'zone': 'zone',
}
km_globe = {
'a': 'semimajor_axis',
'b': 'semiminor_axis',
}
km_std = {
'lat_1': 'lat_1',
'lat_2': 'lat_2',
}
kw_proj = {}
kw_globe = {}
kw_std = {}
for s in srs.split('+'):
s = s.split('=')
if len(s) != 2:
continue
k = s[0].strip()
v = s[1].strip()
try:
v = float(v)
except Exception:
pass
if k == 'proj':
if v == 'longlat':
cl = ccrs.PlateCarree
elif v == 'tmerc':
cl = ccrs.TransverseMercator
kw_proj['approx'] = True
elif v == 'lcc':
cl = ccrs.LambertConformal
elif v == 'merc':
cl = ccrs.Mercator
elif v == 'utm':
cl = ccrs.UTM
elif v == 'stere':
cl = ccrs.Stereographic
elif v == 'ob_tran':
cl = ccrs.RotatedPole
else:
raise NotImplementedError(f'Unknown projection {v}')
if k in km_proj:
if k == 'zone':
v = int(v)
kw_proj[km_proj[k]] = v
if k in km_globe:
kw_globe[km_globe[k]] = v
if k in km_std:
kw_std[km_std[k]] = v
globe = None
if kw_globe:
globe = ccrs.Globe(ellipse='sphere', **kw_globe)
if kw_std:
kw_proj['standard_parallels'] = (kw_std['lat_1'], kw_std['lat_2'])
# mercatoooor
if cl.__name__ == 'Mercator':
kw_proj.pop('false_easting', None)
kw_proj.pop('false_northing', None)
if 'scale_factor' in kw_proj:
kw_proj.pop('latitude_true_scale', None)
elif cl.__name__ == 'Stereographic':
kw_proj.pop('scale_factor', None)
if 'latitude_true_scale' in kw_proj:
kw_proj['true_scale_latitude'] = kw_proj['latitude_true_scale']
kw_proj.pop('latitude_true_scale', None)
elif cl.__name__ == 'RotatedPole':
if 'central_longitude' in kw_proj:
kw_proj['pole_longitude'] = kw_proj['central_longitude'] - 180
kw_proj.pop('central_longitude', None)
else:
kw_proj.pop('latitude_true_scale', None)
try:
return cl(globe=globe, **kw_proj)
except TypeError:
del kw_proj['approx']
return cl(globe=globe, **kw_proj)
def process_crs(crs):
"""
Parses cartopy CRS definitions defined in one of a few formats:
1. EPSG codes: Defined as string of the form "EPSG: {code}" or an integer
2. proj.4 string: Defined as string of the form "{proj.4 string}"
3. cartopy.crs.CRS instance
3. pyproj.Proj or pyproj.CRS instance
4. WKT string: Defined as string of the form "{WKT string}"
5. None defaults to crs.PlateCaree
"""
missing = []
try:
import cartopy.crs as ccrs
except ImportError:
missing.append('cartopy')
try:
import geoviews as gv # noqa
except ImportError:
missing.append('geoviews')
try:
import pyproj
except ImportError:
missing.append('pyproj')
if missing:
raise ImportError(f'Geographic projection support requires: {", ".join(missing)}.')
if crs is None:
return ccrs.PlateCarree()
elif isinstance(crs, ccrs.CRS):
return crs
elif isinstance(crs, str):
all_crs = [
proj
for proj in dir(ccrs)
if callable(getattr(ccrs, proj))
and proj not in ['ABCMeta', 'CRS']
and proj[0].isupper()
or proj == 'GOOGLE_MERCATOR'
]
if crs in all_crs and crs != 'GOOGLE_MERCATOR':
return getattr(ccrs, crs)()
elif crs == 'GOOGLE_MERCATOR':
return getattr(ccrs, crs)
elif isinstance(crs, pyproj.CRS):
crs = crs.to_wkt()
errors = []
if isinstance(crs, (str, int, pyproj.Proj)):
wkt = crs
if isinstance(crs, (str, int)): # epsg codes
try:
wkt = pyproj.CRS.from_epsg(crs).to_wkt()
except Exception as e:
errors.append(e)
try:
return proj_to_cartopy(wkt) # should be all proj4 or wkt strings
except Exception as e:
errors.append(e)
if isinstance(crs, (str, int)):
if isinstance(crs, str):
# pyproj does not expect epsg to be prefixed with `EPSG:`
crs = crs.upper().replace('EPSG:', '').strip()
try:
return ccrs.epsg(crs)
except Exception as e:
errors.append(e)
raise ValueError(
'Projection must be defined as a EPSG code, proj4 string, '
'WKT string, cartopy CRS instance, cartopy CRS class name string, '
'pyproj.Proj, or pyproj.CRS.'
) from Exception(*errors)
def is_list_like(obj):
"""
Adapted from pandas' is_list_like cython function.
"""
return (
# equiv: `isinstance(obj, abc.Iterable)`
hasattr(obj, '__iter__')
and not isinstance(obj, type)
# we do not count strings/unicode/bytes as list-like
and not isinstance(obj, (str, bytes))
# exclude zero-dimensional numpy arrays, effectively scalars
and not (isinstance(obj, np.ndarray) and obj.ndim == 0)
)
def is_tabular(data):
if check_library(data, ['dask', 'streamz', 'pandas', 'geopandas', 'cudf']):
return True
elif check_library(data, 'intake'):
from intake.source.base import DataSource
if isinstance(data, DataSource):
return data.container == 'dataframe'
else:
return False
def is_series(data):
if not check_library(data, ['dask', 'streamz', 'pandas', 'cudf']):
return False
elif isinstance(data, pd.Series):
return True
elif check_library(data, 'streamz'):
import streamz.dataframe as sdf
return isinstance(data, (sdf.Series, sdf.Seriess))
elif check_library(data, 'dask'):
import dask.dataframe as dd
return isinstance(data, dd.Series)
elif check_library(data, 'cudf'):
import cudf
return isinstance(data, cudf.Series)
else:
return False
def check_library(obj, library):
if not isinstance(library, list):
library = [library]
return any([obj.__module__.split('.')[0].startswith(lib) for lib in library])
def is_cudf(data):
if 'cudf' in sys.modules:
from cudf import DataFrame, Series
return isinstance(data, (DataFrame, Series))
def is_dask(data):
if not check_library(data, 'dask'):
return False
import dask.dataframe as dd
return isinstance(data, (dd.DataFrame, dd.Series))
def is_duckdb(data):
if not check_library(data, 'duckdb'):
return False
import duckdb
return isinstance(data, (duckdb.DuckDBPyRelation, duckdb.DuckDBPyConnection))
def is_polars(data):
if not check_library(data, 'polars'):
return False
import polars as pl
return isinstance(data, (pl.DataFrame, pl.Series, pl.LazyFrame))
def is_intake(data):
if 'intake' not in sys.modules:
return False
from intake.source.base import DataSource
return isinstance(data, DataSource)
def is_ibis(data):
if not check_library(data, 'ibis'):
return False
import ibis
return isinstance(data, ibis.Expr)
def is_streamz(data):
if not check_library(data, 'streamz'):
return False
import streamz.dataframe as sdf
return sdf and isinstance(data, (sdf.DataFrame, sdf.Series, sdf.DataFrames, sdf.Seriess))
def is_xarray(data):
if not check_library(data, 'xarray'):
return False
from xarray import DataArray, Dataset
return isinstance(data, (DataArray, Dataset))
def is_xarray_dataarray(data):
if not check_library(data, 'xarray'):
return False
from xarray import DataArray
return isinstance(data, DataArray)
def support_index(data):
"""
HoloViews added in v1.19.0 support for retaining Pandas indexes (no longer
calling .reset_index()).
Update this utility when other data interfaces support that (geopandas, dask, etc.)
"""
return type(data) is pd.DataFrame
def process_intake(data, use_dask):
if data.container not in ('dataframe', 'xarray'):
raise NotImplementedError(
'Plotting interface currently only '
'supports DataSource objects declaring '
'a dataframe or xarray container.'
)
if use_dask:
data = data.to_dask()
else:
data = data.read()
return data
def is_geodataframe(data):
if 'spatialpandas' in sys.modules:
import spatialpandas as spd
if isinstance(data, (spd.GeoDataFrame, spd.dask.DaskGeoDataFrame)):
return True
return (
isinstance(data, pd.DataFrame) and hasattr(data, 'geom_type') and hasattr(data, 'geometry')
)
def process_xarray(
data, x, y, by, groupby, use_dask, persist, gridded, label, value_label, other_dims, kind=None
):
import xarray as xr
if isinstance(data, xr.Dataset):
dataset = data
else:
name = data.name or label or value_label
dataset = data.to_dataset(name=name)
all_vars = list(other_dims) if other_dims else []
for var in [x, y, by, groupby]:
if isinstance(var, list):
all_vars.extend(var)
elif isinstance(var, str):
all_vars.append(var)
if not gridded:
not_found = [
var for var in all_vars if var not in list(dataset.data_vars) + list(dataset.coords)
]
_, extra_vars, extra_coords = process_derived_datetime_xarray(dataset, not_found)
dataset = dataset.assign_coords(**{var: dataset[var] for var in extra_coords})
dataset = dataset.assign(**{var: dataset[var] for var in extra_vars})
data_vars = list(dataset.data_vars)
ignore = (by or []) + (groupby or [])
dims = [c for c in dataset.coords if dataset[c].shape != () and c not in ignore][::-1]
index_dims = [d for d in dims if d in dataset.indexes]
if gridded:
data = dataset
if len(dims) < 2:
dims += [dim for dim in list(data.dims)[::-1] if dim not in dims]
if not (x or y):
for c in dataset.coords:
axis = dataset[c].attrs.get('axis', '')
if axis.lower() == 'x':
x = c
elif axis.lower() == 'y':
y = c
if not (x or y):
x, y = index_dims[:2] if len(index_dims) > 1 else dims[:2]
elif x and not y:
y = [d for d in dims if d != x][0]
elif y and not x:
x = [d for d in dims if d != y][0]
if len(dims) > 2 and kind not in ('table', 'dataset') and not groupby:
dims = list(data.coords[x].dims) + list(data.coords[y].dims)
groupby = [
d for d in index_dims if d not in (x, y) and d not in dims and d not in other_dims
]
else:
if use_dask:
data = dataset.to_dask_dataframe()
data = data.persist() if persist else data
else:
data = dataset.to_dataframe()
if not support_index(data) and len(data.index.names) > 1:
data = data.reset_index()
if len(dims) == 0:
dims = ['index']
if x and not y:
y = dims[0] if x in data_vars else data_vars
elif y and not x:
x = data_vars[0] if y in dims else dims[0]
elif not x and not y:
x, y = dims[0], data_vars
for var in [x, y]:
if isinstance(var, list):
all_vars.extend(var)
elif isinstance(var, str):
all_vars.append(var)
covered_dims = []
for var in all_vars:
if var in dataset.coords:
covered_dims.extend(dataset[var].dims)
leftover_dims = [dim for dim in index_dims if dim not in covered_dims + all_vars]
if groupby is None:
groupby = [c for c in leftover_dims if c not in (by or [])]
return data, x, y, by, groupby
def process_derived_datetime_xarray(data, not_found):
from pandas.api.types import is_datetime64_any_dtype as isdate
extra_vars = []
extra_coords = []
for var in not_found:
if '.' in var:
derived_from = var.split('.')[0]
if isdate(data[derived_from]):
if derived_from in data.coords:
extra_coords.append(var)
else:
extra_vars.append(var)
not_found = [var for var in not_found if var not in extra_vars + extra_coords]
return not_found, extra_vars, extra_coords
def process_derived_datetime_pandas(data, not_found, indexes=None):
from pandas.api.types import is_datetime64_any_dtype as isdate
indexes = indexes or []
extra_cols = {}
for var in not_found:
if '.' in var:
parts = var.split('.')
base_col = parts[0]
dt_str = parts[-1]
if base_col in data.columns:
if isdate(data[base_col]):
extra_cols[var] = getattr(data[base_col].dt, dt_str)
elif base_col == 'index':
if isdate(data.index):
extra_cols[var] = getattr(data.index, dt_str)
elif base_col in indexes:
index = data.axes[indexes.index(base_col)]
if isdate(index):
extra_cols[var] = getattr(index, dt_str)
if extra_cols:
data = data.assign(**extra_cols)
not_found = [var for var in not_found if var not in extra_cols.keys()]
return not_found, data
def process_dynamic_args(x, y, kind, **kwds):
dynamic = {}
arg_deps = []
arg_names = []
for k, v in list(kwds.items()) + [('x', x), ('y', y), ('kind', kind)]:
if isinstance(v, param.Parameter):
dynamic[k] = v
elif panel_available and isinstance(v, pn.widgets.Widget):
dynamic[k] = v
for k, v in kwds.items():
if k not in dynamic and isinstance(v, FunctionType) and hasattr(v, '_dinfo'):
deps = v._dinfo['dependencies']
arg_deps += list(deps)
arg_names += list(k) * len(deps)
return dynamic, arg_deps, arg_names
def filter_opts(eltype, options, backend='bokeh'):
opts = getattr(hv.Store.options(backend), eltype)
allowed = [k for g in opts.groups.values() for k in list(g.allowed_keywords)]
opts = {k: v for k, v in options.items() if k in allowed}
return opts
def _flatten(line):
"""
Flatten an arbitrarily nested sequence.
Inspired by: pd.core.common.flatten
Parameters
----------
line : sequence
The sequence to flatten
Notes
-----
This only flattens list, tuple, and dict sequences.
Returns
-------
flattened : generator
"""
for element in line:
if any(isinstance(element, tp) for tp in (list, tuple, dict)):
yield from _flatten(element)
else:
yield element
def _convert_col_names_to_str(data):
"""
Convert column names to string.
"""
# There's no generic way to rename columns across tabular object types.
# `columns` could refer to anything else on the object, e.g. a dim
# on an xarray DataArray. So this may need to be stricter.
if not hasattr(data, 'columns') or not hasattr(data, 'rename'):
return data
renamed = {
c: str(c) for c in data.columns if not isinstance(c, str) and isinstance(c, Hashable)
}
if renamed:
data = data.rename(columns=renamed)
return data
def instantiate_crs_str(crs_str: str, **kwargs):
"""
Instantiate a cartopy.crs.Projection from a string.
"""
import cartopy.crs as ccrs
if crs_str.upper() == 'GOOGLE_MERCATOR':
return ccrs.GOOGLE_MERCATOR
return getattr(ccrs, crs_str)(**kwargs)
def import_datashader():
datashader = None
try:
import datashader
except ModuleNotFoundError:
raise ModuleNotFoundError(
'The `datashader` package must be installed in order to use '
'datashading features. Install it with pip or conda.'
) from None
return datashader
def relabel(hv_obj, **kwargs):
"""Conditionally relabel a HoloViews object"""
if kwargs:
hv_obj = hv_obj.relabel(**kwargs)
return hv_obj
def redim_(hv_obj, **kwargs):
"""Conditionally redim a HoloViews object"""
if kwargs:
hv_obj = hv_obj.redim(**kwargs)
return hv_obj
def relabel_redim(hv_obj, relabel_kwargs, redim_kwargs):
"""Conditionally relabel and/or redim a HoloViews object"""
if relabel_kwargs:
hv_obj = hv_obj.relabel(**relabel_kwargs)
if redim_kwargs:
hv_obj = hv_obj.redim(**redim_kwargs)
return hv_obj