File size: 5,409 Bytes
4ece8a6
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
importScripts("https://cdn.jsdelivr.net/pyodide/v0.24.1/full/pyodide.js");

function sendPatch(patch, buffers, msg_id) {
  self.postMessage({
    type: 'patch',
    patch: patch,
    buffers: buffers
  })
}

async function startApplication() {
  console.log("Loading pyodide!");
  self.postMessage({type: 'status', msg: 'Loading pyodide'})
  self.pyodide = await loadPyodide();
  self.pyodide.globals.set("sendPatch", sendPatch);
  console.log("Loaded!");
  await self.pyodide.loadPackage("micropip");
  const env_spec = ['https://cdn.holoviz.org/panel/wheels/bokeh-3.3.2-py3-none-any.whl', 'https://cdn.holoviz.org/panel/1.3.6/dist/wheels/panel-1.3.6-py3-none-any.whl', 'pyodide-http==0.2.1', 'holoviews', 'pandas']
  for (const pkg of env_spec) {
    let pkg_name;
    if (pkg.endsWith('.whl')) {
      pkg_name = pkg.split('/').slice(-1)[0].split('-')[0]
    } else {
      pkg_name = pkg
    }
    self.postMessage({type: 'status', msg: `Installing ${pkg_name}`})
    try {
      await self.pyodide.runPythonAsync(`
        import micropip
        await micropip.install('${pkg}');
      `);
    } catch(e) {
      console.log(e)
      self.postMessage({
	type: 'status',
	msg: `Error while installing ${pkg_name}`
      });
    }
  }
  console.log("Packages loaded!");
  self.postMessage({type: 'status', msg: 'Executing code'})
  const code = `
  
import asyncio

from panel.io.pyodide import init_doc, write_doc

init_doc()

"""*Linked Brushing* is a very powerful technique. It's also often called
*Linked Selections* or *Crossfiltering*.

This example is inspired by the HoloViews [Linked Brushing Reference Guide]\
(http://holoviews.org/user_guide/Linked_Brushing.html) and the Plotly blog post
[Introducing Dash HoloViews]\
(https://medium.com/plotly/introducing-dash-holoviews-6a05c088ebe5).

This example uses the *Iris* dataset.
"""
from typing import Tuple

import holoviews as hv
import pandas as pd
import panel as pn
from holoviews import opts
from panel.template import FastListTemplate


@pn.cache
def get_iris_data():
    return pd.read_csv("https://cdn.awesome-panel.org/resources/crossfiltering_holoviews/iris.csv.gz")


ACCENT = "#F08080"

CSS = """
.main .card-margin.stretch_both {
    height: calc(50vh - 65px) !important;
}
"""
if not CSS in pn.config.raw_css:
    pn.config.raw_css.append(CSS)

BOKEH_TOOLS = {
    "tools": ["hover"], "active_tools": ["box_select"]
}


def get_linked_plots() -> Tuple:
    """Returns a tuple (scatter, hist) of linked plots
    
    See http://holoviews.org/user_guide/Linked_Brushing.html
    """

    dataset = hv.Dataset(get_iris_data())

    scatter = hv.Scatter(dataset, kdims=["sepal_length"], vdims=["sepal_width"])
    hist = hv.operation.histogram(dataset, dimension="petal_width", normed=False)

    # pylint: disable=no-value-for-parameter
    selection_linker = hv.selection.link_selections.instance()
    # pylint: disable=no-member
    scatter = selection_linker(scatter).opts(
        opts.Scatter(color=ACCENT, responsive=True, size=10, **BOKEH_TOOLS),
    )
    hist = selection_linker(hist).opts(
        opts.Histogram(color=ACCENT, responsive=True, **BOKEH_TOOLS)
    )

    return scatter, hist


def create_app():
    """Returns the app in a nice FastListTemplate"""
    scatter, hist = get_linked_plots()
    scatter_panel = pn.pane.HoloViews(scatter, sizing_mode="stretch_both")
    hist_panel = pn.pane.HoloViews(hist, sizing_mode="stretch_both")
    
    template = FastListTemplate(
        site="Awesome Panel",
        site_url="https://awesome-panel.org",
        title="Linked Brushing with HoloViews and Bokeh",
        accent=ACCENT,
        main=[
            # We need to wrap in Columns to get them to stretch properly
            pn.Column(scatter_panel, sizing_mode="stretch_both"),
            pn.Column(hist_panel, sizing_mode="stretch_both"),
        ],
    )
    return template

pn.extension()
hv.extension("bokeh")
create_app().servable()


await write_doc()
  `

  try {
    const [docs_json, render_items, root_ids] = await self.pyodide.runPythonAsync(code)
    self.postMessage({
      type: 'render',
      docs_json: docs_json,
      render_items: render_items,
      root_ids: root_ids
    })
  } catch(e) {
    const traceback = `${e}`
    const tblines = traceback.split('\n')
    self.postMessage({
      type: 'status',
      msg: tblines[tblines.length-2]
    });
    throw e
  }
}

self.onmessage = async (event) => {
  const msg = event.data
  if (msg.type === 'rendered') {
    self.pyodide.runPythonAsync(`
    from panel.io.state import state
    from panel.io.pyodide import _link_docs_worker

    _link_docs_worker(state.curdoc, sendPatch, setter='js')
    `)
  } else if (msg.type === 'patch') {
    self.pyodide.globals.set('patch', msg.patch)
    self.pyodide.runPythonAsync(`
    state.curdoc.apply_json_patch(patch.to_py(), setter='js')
    `)
    self.postMessage({type: 'idle'})
  } else if (msg.type === 'location') {
    self.pyodide.globals.set('location', msg.location)
    self.pyodide.runPythonAsync(`
    import json
    from panel.io.state import state
    from panel.util import edit_readonly
    if state.location:
        loc_data = json.loads(location)
        with edit_readonly(state.location):
            state.location.param.update({
                k: v for k, v in loc_data.items() if k in state.location.param
            })
    `)
  }
}

startApplication()