Python：如何更新bokeh中的数据选择？
我是新来的bokeh。
这就是我在做什么。从osmnx我那里获得海地学校和医院的数据。
没有编写所有代码，我到达以下代码
data1=dict(
x=list(schools['x'].values),
y=list(schools['y'].values)
)
data2=dict(
x=list(hospitals['x'].values),
y=list(hospitals['y'].values)
)
building = 'Schools'
buildings = {
'Schools': {
'title': 'Schools',
'data': data1,
'color': 'black'
},
'Hospitals': {
'title': 'Hospitals',
'data': data2,
'color': 'red'
}
}
building_select = Select(value=building, title='Building', options=sorted(buildings.keys()))
我想通过选择它来更改学校和医院之间的可视化。我定义了更改要获取的数据和颜色的函数。
def returnInfo(building):
dataPoints = buildings[building]['data']
color = buildings[building]['color']
return dataPoints, color
dataPoints, color = returnInfo(building)
我定义功能 make_plot
def make_plot(dataPoints, title, color):
TOOLS = "pan, wheel_zoom, reset,save"
p = figure(plot_width=800,
tools=TOOLS,
x_axis_location=None,
y_axis_location=None)
# Add points on top (as black points)
buildings = p.circle('x', 'y', size=4, source=data1, color=color)
hover_buildings = HoverTool(renderers = [buildings], point_policy="follow_mouse", tooltips = [("(Long, Lat)", "($x, $y)")])
p.add_tools(hover_buildings)
return p
plot = make_plot（数据点，“ +建筑物[building] ['title']的数据，颜色）
然后我更新
def update_plot(attrname, old, new):
building = building_select.value
p.title.text = "Data for " + buildings[building]['title']
src = buildings[building]['data']
dataPoints, color = returnInfo(building)
dataPoints.update
building_select.on_change('value', update_plot)
controls = column(building_select)
curdoc().add_root(row(plot, controls))
但它不起作用：即，即使有光标，我也无法将点从学校更改为医院。更新部分中的错误在哪里？
作为第一个解决方案，我建议使用legend.click_plolicy = 'hide'切换建筑物在地图上的可见性（Bokeh v1.1.0）
from bokeh.models import ColumnDataSource
from bokeh.plotting import figure, show
from bokeh.tile_providers import CARTODBPOSITRON_RETINA
import osmnx as ox
amenities = ['hospital', 'school']
for i, amenity in enumerate(amenities):
buildings = ox.pois_from_address("Port-au-Prince, Haiti", amenities = [amenity], distance = 3500)[['geometry', 'name', 'element_type']]
for item in ['way', 'relation']:
buildings.loc[buildings.element_type == item, 'geometry'] = buildings[buildings.element_type == item]['geometry'].map(lambda x: x.centroid)
buildings.name.fillna('Hospital' if i == 0 else 'School', inplace = True)
amenities[i] = buildings.to_crs(epsg = 3857)
p = figure(title = "Port-au-Prince, Haiti", tools = "pan,wheel_zoom,hover,reset", x_range = (-8057000, -8048500), y_range = (2098000, 2106000),
tooltips = [('Name', '@name'), ("(Long, Lat)", "($x, $y)")], x_axis_location = None, y_axis_location = None, active_scroll = 'wheel_zoom')
p.add_tile(CARTODBPOSITRON_RETINA)
p.grid.grid_line_color = None
for i, b in enumerate(amenities):
source = ColumnDataSource(data = dict(x = b.geometry.x, y = b.geometry.y, name = b.name.values))
p.circle('x', 'y', color = 'red' if i == 0 else 'blue', source = source, legend = 'Hospital' if i == 0 else 'School')
p.legend.click_policy = 'hide'
show(p)
如果您想要Select小部件，那么这里是另一种选择（Bokeh v1.1.0）：
from bokeh.models import ColumnDataSource, Column, Select, CustomJS
from bokeh.plotting import figure, show
from bokeh.tile_providers import CARTODBPOSITRON_RETINA
import osmnx as ox
amenities = ['hospital', 'school']
for i, amenity in enumerate(amenities):
buildings = ox.pois_from_address("Port-au-Prince, Haiti", amenities = [amenity], distance = 3500)[['geometry', 'name', 'element_type']]
for item in ['way', 'relation']:
buildings.loc[buildings.element_type == item, 'geometry'] = buildings[buildings.element_type == item]['geometry'].map(lambda x: x.centroid)
buildings.name.fillna('Hospital' if i == 0 else 'School', inplace = True)
buildings = buildings.to_crs(epsg = 3857)
amenities[i] = dict(x = list(buildings.geometry.x), y = list(buildings.geometry.y), name = list(buildings.name.values), color = (['red'] if i == 0 else ['blue']) * len(buildings.name.values))
source = ColumnDataSource(amenities[0])
p = figure(title = "Hospitals", tools = "pan,wheel_zoom,hover,reset", x_range = (-8057000, -8048500), y_range = (2098000, 2106000),
tooltips = [('Name', '@name'), ("(Long, Lat)", "($x, $y)")], x_axis_location = None, y_axis_location = None, active_scroll = 'wheel_zoom')
p.add_tile(CARTODBPOSITRON_RETINA)
p.circle(x = 'x', y = 'y', color = 'color', source = source)
p.grid.grid_line_color = None
code = ''' source.data = (cb_obj.value == 'Hospitals' ? data[0] : data[1]); p.title.text = cb_obj.value; '''
select = Select(options = ['Hospitals', 'Schools'], callback = CustomJS(args=dict(p = p, source = source, data = amenities), code = code))
show(Column(p, select))
让我知道您是否需要对此代码的任何解释。
以下是使您的代码正常工作所需的更改：
在您的make_plot方法中，由于您想在选择更改时更新绘图的标题，因此将
p = figure(plot_width=800,
tools=TOOLS,
x_axis_location=None,
y_axis_location=None)
和
p = figure(plot_width=800,
tools=TOOLS,
title=title,
x_axis_location=None,
y_axis_location=None)
另外，由于您想要更新建筑物的数据和颜色，因此请buildings在方法中返回too，以便完整的方法现在如下所示：
def make_plot(dataPoints, title, color):
TOOLS = "pan, wheel_zoom, reset,save"
p = figure(plot_width=800,
tools=TOOLS,
title=title,
x_axis_location=None,
y_axis_location=None)
# Add points on top (as black points)
buildings = p.circle('x', 'y', size=4, source=data1, color=color)
hover_buildings = HoverTool(renderers = [buildings], point_policy="follow_mouse", tooltips = [("(Long, Lat)", "($x, $y)")])
p.add_tools(hover_buildings)
return p, buildings
接下来，而不是调用
plot = make_plot(dataPoints, "Data for " + buildings[building]['title'], color)
您还需要将返回的建筑物也保存在变量中，以便可以直接更新。所以现在你的电话看起来像
plot, b = make_plot(dataPoints, "Data for " + buildings[building]['title'], color)
最后，更改你的update_plot方法，使其看起来像这样：
def update_plot(attrname, old, new):
building = building_select.value
plot.title.text = "Data for " + buildings[building]['title']
src = buildings[building]['data']
dataPoints, color = returnInfo(building)
b.data_source.data = dataPoints
b.glyph.fill_color = color
通过这些更改，它将按预期工作。请参阅所附结果。使用的样本数据是：
data1=dict(
x=[1,2,3],
y=[2,1,3]
)
data2=dict(
x=[1,2,3],
y=[1,3,2]
)
