GeoViews：具有 matplotlib 后端的 GeoDataFrames 的分类图例

2024-02-22

已安装的软件包

geoviews 1.9.1.，matplotlib 3.4.2。

我正在尝试做什么

For the Bokeh后端通过添加分类图例GeoViews是通过代理艺术家完成的，如中所述卡特里娜飓风路径示例 https://geoviews.org/gallery/bokeh/katrina_track.html，我设法让它发挥作用，但是这对Matplotlib后端？相应的卡特里娜飓风跟踪案例的 mpl 示例 https://geoviews.org/gallery/matplotlib/katrina_track.html#matplotlib-gallery-katrina-track，特别是不包括图例。另一个mpl带图例的示例都使用颜色条。

The HoloViews 图例示例 http://holoviews.org/gallery/demos/matplotlib/legend_example.html表明这是自动完成的，所以我认为这同样适用于GeoViews但是当尝试使用 GeoDataFrames 作为输入来重现示例时gv.Polygons，没有出现图例。

可重现的例子

import pandas as pd
import geopandas as gpd
import geoviews as gv
from geoviews import opts

gv.extension('matplotlib')

d1 = {'use': {0: 'Residential', 1: 'Residential'},
'geometry': {0: 'POLYGON ((13.80961103741604 51.04076975651729, 13.80965521888065 51.04079016168103, 13.80963851766593 51.04080454197601, 13.80959433642561 51.04078412781548, 13.80961103741604 51.04076975651729))',
1: 'POLYGON ((13.80977831740752 51.04313480566009, 13.80987122363639 51.04306085051974, 13.8099989591537 51.04312462457182, 13.80995486494384 51.04315973323087, 13.8099651184249 51.04316486464228, 13.80991634926543 51.04320371166482, 13.80977831740752 51.04313480566009))'}}

gdf1 = gpd.GeoDataFrame(pd.DataFrame(d1), geometry=gpd.GeoSeries.from_wkt(pd.DataFrame(d1)['geometry']), crs="EPSG:4326")

d2 = {'geometry': {1: 'POLYGON ((13.80894179055831 51.04544128170094, 13.80952887156242 51.0450399782091, 13.80954152432486 51.04504668985658, 13.80896834397535 51.04545611172818, 13.80894179055831 51.04544128170094))'}}

gdf2 = gpd.GeoDataFrame(pd.DataFrame(d2), geometry=gpd.GeoSeries.from_wkt(pd.DataFrame(d2)['geometry']), crs="EPSG:4326")


feature1 = gv.Polygons(gdf1, group="group1", label='label1')
feature2 = gv.Polygons(gdf2, group="group2", label='label2')

layout = feature1.opts(color='red') * feature2.opts(color='lightgrey')

layout.opts(
            opts.Polygons('group1', cmap=['red'], edgecolor='black', linewidth=0.5, xaxis=None, yaxis=None),
            opts.Polygons('group2', cmap=['lightblue'], edgecolor='blue', linewidth=0.5),
            opts.Overlay(fig_size=500)
        )
        
gv.output(layout)

任何指示将不胜感激（如果可能的话，在更早的相关SO问题 https://stackoverflow.com/questions/68318769/geoviews-applying-matplotlib-styling-parameters-to-polygons-elements我几周前的作品）。

这可能是由于这个已知问题仍然悬而未决：https://github.com/holoviz/geoviews/issues/450 https://github.com/holoviz/geoviews/issues/450

您的示例和链接问题中的示例都会导致此错误：

File ~\.conda\envs\py38\lib\site-packages\matplotlib\legend_handler.py:768, in HandlerTuple.create_artists(self, legend, orig_handle, xdescent, ydescent, width, height, fontsize, trans)
    766 for handle1 in orig_handle:
    767     handler = legend.get_legend_handler(handler_map, handle1)
--> 768     _a_list = handler.create_artists(
    769         legend, handle1,
    770         next(xds_cycle), ydescent, width, height, fontsize, trans)
    771     a_list.extend(_a_list)
    773 return a_list

AttributeError: 'NoneType' object has no attribute 'create_artists'

本文内容由网友自发贡献，版权归原作者所有，本站不承担相应法律责任。如您发现有涉嫌抄袭侵权的内容，请联系:hwhale#tublm.com(使用前将#替换为@)

geoviews