Question

我试图复制这种将连续值映射到HeatMap实例的LinearColorMapper样式：http://bokeh.pydata.org/en/latest/docs/gallery/unemployment.html 我想制作HeatMap（带charts或rect），然后添加single selection widget以选择obsv_id，然后选择slider widget }浏览dates。

但是，我在HeatMap本身与单obsv_id / date对一起遇到了麻烦。在创建此HeatMap时我做错了什么？这基本上是size变量和loc变量的3x3矩形图。

奖金：您能帮助我/就如何连接这些小部件的输出来控制情节提供一些建议吗？

我看到了这些帖子，但所有示例都使用实际的十六进制颜色作为列表而不是使用连续度量进行映射： python bokeh, how to make a correlation plot? http://bokeh.pydata.org/en/latest/docs/gallery/categorical.html

# Init
import numpy as np
import pandas as pd
from bokeh.plotting import figure, output_notebook, output_file, reset_output, show, ColumnDataSource
from bokeh.models import LinearColorMapper
reset_output()
output_notebook()

np.random.seed(0)

# Coords
dates = ["07-3","07-11","08-6","08-28"]
#locs = ["air","water","earth"]
locs = [0,1,2]
size = [3.0, 0.2, 0.025]
observations = ["obsv_%d"%_ for _ in range(10)]


# Data
Ar_tmp = np.zeros(( len(dates)*len(locs)*len(size)*len(observations), 5 ), dtype=object)

i = 0
for date in dates:
    for loc in locs:
        for s in size:
            for obsv_id in observations:
                Ar_tmp[i,:] = np.array([obsv_id, date, loc, s, np.random.random()])
                i += 1
DF_tmp = pd.DataFrame(Ar_tmp, columns=["obsv_id", "date", "loc", "size", "value"])
DF_tmp["value"] = DF_tmp["value"].astype(float)
DF_tmp["size"] = DF_tmp["size"].astype(float)
DF_tmp["loc"] = DF_tmp["loc"].astype(float)
#     obsv_id   date    loc   size     value
# 0    obsv_0   07-3    air    3.0  0.548814
# 1    obsv_1   07-3    air    3.0  0.715189
# 2    obsv_2   07-3    air    3.0  0.602763
# 3    obsv_3   07-3    air    3.0  0.544883
# 4    obsv_4   07-3    air    3.0  0.423655

mapper = LinearColorMapper(low = DF_tmp["value"].min(), high = DF_tmp["value"].max())

# # Create Heatmap of a single observation and date pair
query_idx = set(DF_tmp.index[DF_tmp["obsv_id"] == "obsv_0"]) & set(DF_tmp.index[DF_tmp["date"] == "08-28"])

# p = HeatMap(data=DF_tmp.loc[query_idx,:], x="loc", y="size", values="value")
p = figure()
p.rect(x="loc", y="size", 
       source=ColumnDataSource(DF_tmp.loc[query_idx,:]),
       fill_color={'field': 'value', 'transform': mapper},
       line_color=None)
show(p)

我的错误：

# Javascript error adding output!
# TypeError: Cannot read property 'length' of null
# See your browser Javascript console for more details.

Answer 1

您必须向LinearColorMapper提供palette。例如：

mapper = LinearColorMapper(
    palette='Magma256',
    low=DF_tmp["value"].min(),
    high=DF_tmp["value"].max()
)

来自LinearColorMapper doc：

class LinearColorMapper(palette=None, **kwargs)
将[低，高]范围内的数字线性地映射到一系列颜色（调色板）。

与您的例外无关，但您还需要将width和height个参数传递给p.rect()。

如何使用Python 3在连续的彩色地图中制作`Bokeh`中的`Heatmaps`？

1 个答案: