如何用gv.Polygons代替gv.Shape成功绘制合唱曲

Question

进一步测试后的

• 更新20/02/20：

我有两个其他形状的文件(一个代表英国的邮政编码地区和一个由Parl选区)。在使用gv.Shape时，我不需要设置用于成功绘图的投影，这与我在最初的文章中讨论的投影不同。我还可以使用gv.Polygons成功地为这些人制作合唱：

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当我检查这些文件所使用的投影时，它是{'init': 'epsg:4326'}，因此我更改了lad19 shapefile上的投影，以匹配该投影：

gdf = gdf.to_crs(epsg=4326)

然而，当我试图使用gv.Polygons生成合唱团时，它失败了，其错误与我之前记录的第一个错误相同。

这感觉好像我已经接近解决方案了，有谁有什么建议吗？

• 原始开始：

我下载了这个英国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 method)成功地创建一个交互式的英国合唱团：

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，我想转到一个更具交互性的地块上，用户在地图左边选择一个多边形，并为给定的多边形/地方当局区选择一个表格和/或其他一些地块，如：http://holoviews.org/gallery/demos/bokeh/choropleth_data_link.html

要做到这一点，我必须从使用gv.Shape切换到gv.Polygons，无论我尝试什么，我都无法使它成功地工作。

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

因此，我想我可能需要显式地设置kdim：

# 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。

在阅读这些错误信息链接中的用户指南时，它说“表格数据有固定的列标题列表，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的数据源自然符合这种格式。”。

我尝试过用一个shapefile创建gdf，从csv和羽毛格式创建demo_file，但都没有成功。

我尝试的最后一件事是将gdf与demo_file df合并，然后再尝试绘制合唱图：

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

但正如你所见，我又犯了同样的错误。

有趣的一点是，当我检查合并finalgdf上使用的投影时，它返回为NoneType：

In [19]: type(finalgdf.crs)                                                                                      
Out[19]: NoneType

所以我把它设置为OSGB：

In [20]: finalgdf.crs = {'init': 'epsg:27700'} 
    ...: finalgdf.crs                                                                                            
Out[20]: {'init': 'epsg:27700'}

然后重复了我上一次的阴谋尝试，但是我又犯了同样的错误：

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

我完全迷失了方向。有人能帮我用gv.Polygons而不是gv.Shape成功地再现我的英国合唱团吗？

否则，如果有一种方法可以成功地将使用gv.Shape生成的合唱团链接到数据表和/或http://holoviews.org/gallery/demos/bokeh/choropleth_data_link.html中的其他情节，那就太好了。我也尝试过，但也失败了。

谢谢

我正在使用OSX (10.15.2 (19C57))，firefox 74.0 (64位)，我正在使用一本木星笔记本。

软件版本：(试图包括相关的，因为它们不适合他们在这里-如果我错过任何一个，让我知道，我会添加它们)

# Name                    Version                   Build  Channel
_anaconda_depends         2019.03                  py37_0  
anaconda                  custom                   py37_1  
anaconda-client           1.7.2                    py37_0  
anaconda-project          0.8.4                      py_0  
arrow-cpp                 0.13.0           py37h8cfbac2_0   
bokeh                     1.4.0                    py37_0  
cairo                     1.14.12              hc4e6be7_4  
cartopy                   0.17.0           py37haea56ea_1   
colorcet                  2.0.2                      py_0    pyviz
cython                    0.29.14          py37h0a44026_0  
descartes                 1.1.0                      py_4    conda-forge
feather-format            0.4.0                   py_1003    conda-forge
fingertips-py             0.2                      pypi_0    pypi
flask                     1.1.1                      py_0  
geopandas                 0.6.1                      py_0  
geos                      3.7.1                h0a44026_0  
geoviews                  1.6.5                      py_0    pyviz
geoviews-core             1.6.5                      py_0    pyviz  
holoviews                 1.12.7                     py_0    pyviz
hvplot                    0.5.2                      py_0    pyviz
ipykernel                 5.1.3            py37h39e3cac_0  
ipython                   7.9.0            py37h39e3cac_0  
ipython_genutils          0.2.0                    py37_0  
ipywidgets                7.5.1                      py_0  
jupyter                   1.0.0                    py37_7  
jupyter_client            5.3.4                    py37_0  
jupyter_console           6.0.0                    py37_0  
jupyter_core              4.6.1                    py37_0  
jupyterlab                1.2.3              pyhf63ae98_0  
jupyterlab_server         1.0.6                      py_0  
markdown                  3.1.1                    py37_0  
matplotlib                3.1.1            py37h54f8f79_0   
notebook                  6.0.2                    py37_0  
numpy                     1.17.3           py37h4174a10_0  
pandas                    0.25.3           py37h0a44026_0   
panel                     0.8.0                      py_0    pyviz
param                     1.9.2                      py_0    pyviz
parquet-cpp               1.5.1                         2    conda-forge 
plotly                    4.3.0                      py_0    plotly
plotly_express            0.4.1                      py_0    plotly
proj4                     5.2.0                h0a44026_1  
pyarrow                   0.13.0           py37hb37e6aa_0    conda-forge  
python                    3.7.5                h359304d_0  
scikit-image              0.15.0           py37h0a44026_0  
scikit-learn              0.21.3           py37h27c97d8_0  
scipy                     1.3.1            py37h1410ff5_0  
seaborn                   0.9.0              pyh91ea838_1   
shapely                   1.6.4            py37he8793f5_0  

Answer 1

经过进一步的测试，我创建了一个额外的问题，它更简洁地确定了这个错误的原因，更重要的是提供了一个解决方案：

gv.Polygons DataError When Using OSGB Projection

将此问题作为副本结束。