- 进一步测试后更新 20/02/20：
我还有 2 个其他 shapefile（一个用于英国邮政编码区，一个用于 Parl 选区）。与这些一起使用 gv.Shape 时，我不需要设置用于成功绘制的投影，这与我在原始帖子中讨论的不同。我还可以使用 gv.Polygons 成功地为这些生成 choropleths：
当我检查这些使用的投影时{'init': 'epsg:4326'}，我更改了 lad19 shapefile 上的投影以匹配：
gdf = gdf.to_crs(epsg=4326)
但是，当我尝试使用 gv.Polygons 生成 choropleth 时，它失败并出现与我之前记录的第一个错误相同的错误。
这感觉就像我接近解决方案一样，有人有什么建议吗？
- 原始开始：
我已经下载了这个英国 shapefile： https ://geoportal.statistics.gov.uk/datasets/local-authority-districts-december-2019-boundaries-uk-buc
我可以使用以下代码（ gv.Shape 方法）成功创建交互式 UK Choropleth ：
import pandas as pd
import numpy as np
import geopandas as gpd
import random
import copy
import feather
import matplotlib.pyplot as plt
import seaborn as sns
import plotly.graph_objects as go
import plotly.express as px
import panel as pn
import holoviews as hv
import geoviews as gv
import geoviews.feature as gf
import geoviews.tile_sources as gvts
import cartopy
import cartopy.feature as cf
from geoviews import opts
from holoviews import opts, streams
from holoviews.plotting.links import DataLink
from cartopy import crs as ccrs
import hvplot.pandas # noqa
import colorcet as cc
from colorcet.plotting import swatch
sns.set_style()
hv.extension("bokeh","plotly")
# TO SET NUMBER OF ROWS DISPLAYED:
pd.set_option("display.min_rows",0)
# TO SET NUMBER OF COLUMNS DISPLAYED:
pd.set_option("display.max_columns",0)
# LOAD SHAPEFILE USING gv.Shape
In [3]: shapefile = "../level3_LAD19_CONTAINS_4_LE
...: VELS_OF_DETAIL/Local_Authority_Districts_December_2019_Boundaries_UK_BUC
...: /Local_Authority_Districts_December_2019_Boundaries_UK_BUC.shp"
...: gv.Shape.from_shapefile(shapefile, crs=ccrs.OSGB())
Out[3]: :Polygons [Longitude,Latitude]
In [4]: # IDENTIFY WHICH ATTRIBUTES ARE IN SHAPEFILE - SO WE KNOW WHICH ATTRIBUTE TO JOIN ON:
...: shapes = cartopy.io.shapereader.Reader(shapefile)
...: list(shapes.records())[0]
Out[4]: <Record: <shapely.geometry.polygon.Polygon object at 0x1c34bc0550>, {'objectid': 1, 'lad19cd': 'E06000001', 'lad19nm': 'Hartlepool', 'lad19nmw': None, 'bng_e': 447160, 'bng_n': 531474, 'long': -1.27018, 'lat': 54.67614, 'st_areasha': 96845510.24630864, 'st_lengths': 50305.32505760145}, <fields>>
# LOAD DF THAT CONTAINS ALL 382 UK LOCAL AUTHORITY DISTRICTS:
In [5]: demo_file = pd.read_feather("../stack_overflow_demo_190320.feather")
...: demo_file.head()
Out[5]:
lad19_code lad19_name geography total_population
0 E06000047 County Durham Unitary Authority 526980
1 E06000005 Darlington Unitary Authority 106566
2 E06000001 Hartlepool Unitary Authority 93242
3 E06000002 Middlesbrough Unitary Authority 140545
4 E06000057 Northumberland Unitary Authority 320274
# SUCCESSFULLY PLOT UK CHOROPLETH:
In [6]: lad19_heatmap = gv.Shape.from_records(
...: shapes.records(),
...: demo_file,
...: on={"lad19cd":"lad19_code"},
...: value="total_population",
...: index="lad19_name", label = "Local Authority Districts UK Population",
...: crs=ccrs.OSGB()).opts(tools=["hover","tap"],
...: cmap = "Reds", colorbar=True,
...: hover_line_color="blue", hover_alpha=0.2,
...: line_width = 2, show_legend=True,
...: legend_position="top",
...: width = 600, height = 800)
...:
...: lad19_heatmap
Out[6]: :Polygons [Longitude,Latitude] (lad19_name,total_population)
我的问题是我想转向更具交互性的绘图，即用户在左侧的地图上选择一个多边形，并在右侧为给定的多边形/地方当局区域显示一个表格和/或其他一些绘图： http://holoviews.org/gallery/demos/bokeh/choropleth_data_link.html
为此，我必须从使用 gv.Shape 切换到 gv.Polygons，无论我尝试什么，我都无法让它成功工作。
不成功的 gv.Polygons 方法：
# LOAD MY SHAPEFILE AS A GEOPANDAS DATAFRAME:
In [10]: gdf = gpd.read_file("../level3_LAD19_CONTAINS_4_LEVELS_OF_DETAIL/Local_Aut
...: hority_Districts_December_2019_Boundaries_UK_BUC/Local_Authority_Districts_December_2019_Boundaries_UK_B
...: UC.shp")
...: gdf.head()
Out[10]:
objectid lad19cd lad19nm lad19nmw bng_e bng_n long lat st_areasha st_lengths geometry
0 1 E06000001 Hartlepool None 447160 531474 -1.27018 54.676140 9.684551e+07 50305.325058 POLYGON ((448986.025 536729.674, 453194.600 53...
1 2 E06000002 Middlesbrough None 451141 516887 -1.21099 54.544670 5.290846e+07 34964.406313 POLYGON ((451752.698 520561.900, 452424.399 52...
2 3 E06000003 Redcar and Cleveland None 464361 519597 -1.00608 54.567520 2.486791e+08 83939.752513 POLYGON ((451965.636 521061.756, 454348.400 52...
3 4 E06000004 Stockton-on-Tees None 444940 518183 -1.30664 54.556911 2.071591e+08 87075.860824 POLYGON ((451965.636 521061.756, 451752.698 52...
4 5 E06000005 Darlington None 428029 515648 -1.56835 54.535339 1.988128e+08 91926.839545 POLYGON ((419709.299 515678.298, 419162.998 51...
# In the previous step I had no way to specify the projection used, so here I confirm that OSGB is used:
In [11]: gdf.crs
Out[11]: {'init': 'epsg:27700'}
我在这里检查了https://spatialreference.org/ref/epsg/osgb-1936-british-national-grid/这似乎是所需的投影，即 OSGB。
# PLOT JUST ON THE GDF (HAS PROJECTION VALUE SET), NOT THE MERGED DF AND GDF
In [12]:gv.Polygons(gdf, vdims='lad1nm'
...: ).opts(projection=ccrs.OSGB(),
...: tools=['hover','tap'],
...: width=450, height=600,
...: color_index='total_population',
...: colorbar=True
...: )
DataError: Expected Polygons instance to declare two key dimensions corresponding to the geometry coordinates but 3 dimensions were found which did not refer to any columns.
GeoPandasInterface expects a list of tabular data, for more information on supported datatypes see http://holoviews.org/user_guide/Tabular_Datasets.html
所以我认为我可能必须明确设置 kdims：
# PLOT JUST ON THE GDF, NOT THE MERGED DF AND GDF (HAS PROJECTION VALUE SET)
In [13]: gv.Polygons(gdf, kdims=["long","lat"],vdims='lad1nm'
...: ).opts(projection=ccrs.OSGB(),
...: tools=['hover','tap'],
...: width=450, height=600,
...: color_index='total_population',
...: colorbar=True
...: )
DataError: Expected Polygons instance to declare two key dimensions corresponding to the geometry coordinates but 1 dimensions were found which did not refer to any columns.
GeoPandasInterface expects a list of tabular data, for more information on supported datatypes see http://holoviews.org/user_guide/Tabular_Datasets.html
这给了我一个与以前非常相似的错误。
通过阅读这些错误消息链接中的用户指南，它说“表格数据具有固定的列标题列表，其值存储在任意长的行列表中。电子表格、关系数据库、CSV 文件和许多其他典型数据源自然适合变成这种格式。”
我尝试使用从 csv 和羽毛格式的 shapefile 和 demo_file 创建的 gdf 进行此操作，但均未成功。
我尝试的最后一件事是将 gdf 与 demo_file df 合并，然后尝试再次绘制等值线：
In [15]: # NEED TO MERGE demo_file DF WITH gdf BEFORE PLOTTING POLYGONS:
...: finalgdf = gpd.GeoDataFrame(pd.merge(demo_file, gdf, left_on="lad19_code",right_on="lad19cd"))
...: finalgdf.drop(columns=["lad19_code","lad19_name"],inplace=True)
...: finalgdf.head()
Out[15]:
geography total_population objectid lad19cd lad19nm lad19nmw bng_e bng_n long lat st_areasha st_lengths geometry
0 Unitary Authority 526980 45 E06000047 County Durham None 410381 532242 -1.84050 54.685131 2.231126e+09 264032.927496 POLYGON ((411575.398 556785.301, 413248.799 55...
1 Unitary Authority 106566 5 E06000005 Darlington None 428029 515648 -1.56835 54.535339 1.988128e+08 91926.839545 POLYGON ((419709.299 515678.298, 419162.998 51...
2 Unitary Authority 93242 1 E06000001 Hartlepool None 447160 531474 -1.27018 54.676140 9.684551e+07 50305.325058 POLYGON ((448986.025 536729.674, 453194.600 53...
3 Unitary Authority 140545 2 E06000002 Middlesbrough None 451141 516887 -1.21099 54.544670 5.290846e+07 34964.406313 POLYGON ((451752.698 520561.900, 452424.399 52...
4 Unitary Authority 320274 54 E06000057 Northumberland None 395322 600699 -2.07523 55.300369 5.033705e+09 445104.766524 MULTIPOLYGON (((391123.704 649427.867, 391525....
In [18]: gv.Polygons(finalgdf, vdims='lad1nm',
...: ).opts(projection=ccrs.OSGB(),
...: tools=['hover','tap'],
...: width=450, height=600,
...: color_index='total_population',
...: colorbar=True
...: )
DataError: Expected Polygons instance to declare two key dimensions corresponding to the geometry coordinates but 3 dimensions were found which did not refer to any columns.
GeoPandasInterface expects a list of tabular data, for more information on supported datatypes see http://holoviews.org/user_guide/Tabular_Datasets.html
但正如你所看到的，我又遇到了同样的错误。
有趣的一点是，当我检查在合并的 finalgdf 上使用的投影时，它返回为 NoneType：
In [19]: type(finalgdf.crs)
Out[19]: NoneType
所以我将它设置为 OSGB：
In [20]: finalgdf.crs = {'init': 'epsg:27700'}
...: finalgdf.crs
Out[20]: {'init': 'epsg:27700'}
然后重复了我上次的情节尝试，但是我又遇到了同样的错误：
In [21]: gv.Polygons(finalgdf, vdims='lad1nm',
...: ).opts(projection=ccrs.OSGB(),
...: tools=['hover','tap'],
...: width=450, height=600,
...: color_index='total_population',
...: colorbar=True
...: )
DataError: Expected Polygons instance to declare two key dimensions corresponding to the geometry coordinates but 3 dimensions were found which did not refer to any columns.
GeoPandasInterface expects a list of tabular data, for more information on supported datatypes see http://holoviews.org/user_guide/Tabular_Datasets.html
我完全输了。谁能帮助我使用 gv.Polygons 而不是 gv.Shape 成功地重新创建我的英国等值线？
如果做不到这一点，如果有一种方法可以按照http://holoviews.org/gallery/demos/bokeh/choropleth_data_link.html将我使用 gv.Shape 生成的 choropleth 成功链接到数据表和/或其他图，那么那将是伟大的。我也尝试过但也未能成功。
谢谢
我正在使用 OSX (10.15.2 (19C57))、firefox 74.0 (64-bit) 并且我正在使用 Jupyter Notebook
软件版本：（试图包括相关的，因为这里不能全部适合它们 - 如果我遗漏了任何让我知道，我会添加它们）
# Name Version Build Channel
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anaconda custom py37_1
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