主页 / coding / 问题 / 77560983
Accepted
KansaiRobot
Asked: 2023-11-28 10:18:31 +0800 CST

根据数据绘制颜色

  • 772

我想绘制一些数据，但颜色取决于某些条件。理想情况下，我想在plotly和matplotlib（单独的脚本）中执行此操作

数据

例如我有以下数据

import pandas as pd

data = {
    'X': [1, 2, 3, 4, 5,6,7,8,9,10],
    'Y': [5, 4, 3, 2, 1,2,3,4,5,5],
    'XL': [2,    None, 4,    None, None,None,4,5,None,3],
    'YL': [3,    None, 2,    None, None,None,5,6,None,4],
    'XR': [None, 4,    None, 1,    None,None,None,4,5,4],
    'YR': [None, 3,    None, 5,    None,None,None,3,4,4]
}

df = pd.DataFrame(data)

简单的情节

所以用 matplotlib

import matplotlib.pyplot as plt
fig, ax = plt.subplots()

# Plot X, Y
ax.plot(df['X'], df['Y'], linestyle='-', marker='o')

# Update plot settings
ax.set_title('Trajectory Plot')
ax.set_xlabel('X-axis')
ax.set_ylabel('Y-axis')

# Show the plot
plt.show()

并有情节地

import plotly.graph_objects as go

# Create a scatter plot
fig = go.Figure(data=go.Scatter(x=df['X'], y=df['Y'], mode='lines+markers'))

# Update layout for better visibility
fig.update_layout(
    title='Trajectory Plot',
    xaxis_title='X-axis',
    yaxis_title='Y-axis',
)

# Show the plot
fig.show()

问题

我想修改脚本，以便我可以根据 和 对是否存在使用不同的(XL,YL)颜色(XR,YR)。

  • 灰色：不存在
  • 红色：仅存在XL、YL
  • 蓝色：仅存在XR、YR
  • 绿色：两者都存在

最后应该是这样的（原谅我画的很粗糙，我把原来的蓝线涂掉了）

如何在 matplotlib 和plotly 中添加它？

在此输入图像描述

python

2 个回答

  1. Best Answer

    IIUC您可以使用 matplotlib 的LineCollection ，请参阅此处的示例

    from matplotlib.collections import LineCollection
from matplotlib.colors import BoundaryNorm, ListedColormap

# COLOR map
arr = np.array(['green']*len(df), dtype=str) # both exist # default
arr[df['XL'].isna() & df['XR'].isna()] = 'grey' # none exist
arr[~df['XL'].isna() & df['XR'].isna()] = 'red' # only L
arr[df['XL'].isna() & ~df['XR'].isna()] = 'blue' # only R

# generate line-segments
points = np.array([df['X'], df['Y']]).T.reshape(-1, 1, 2)
segments = np.concatenate([points[:-1], points[1:]], axis=1)
fig, ax = plt.subplots()
lc = LineCollection(segments, colors=arr)

lc.set_linewidth(2)
line = ax.add_collection(lc)

# add a scatter for point markers
ax.scatter(df['X'], df['Y'], c=arr)

ax.set_xlim(df['X'].min()-1, df['X'].max()+1)
ax.set_ylim(df['Y'].min()-.1, df['Y'].max()+.1)
plt.show()

    输出：

    在此输入图像描述

    对于情节，您可以拥有的最佳解决方案是：

    import plotly.graph_objects as go
import itertools as it

# create coordinate  pairs
x_pairs = it.pairwise(df['X'])
y_pairs = it.pairwise(df['Y'])

# create base figure
fig = go.Figure()

# add traces (line segments)
for x, y, color in zip(x_pairs, y_pairs, arr):
    fig.add_trace(
        go.Scatter(
            x=x,
            y=y, 
            mode='lines+markers', 
            line={'color': color}
        )
    )
    
fig.update_layout(showlegend=False)

    输出：

    在此输入图像描述

    • 2

  2. 一种解决方案是首先绘制整个数据集，而不使用标记。然后，最重要的是，根据您提到的条件绘制彩色标记。

    import pandas as pd
import matplotlib.pyplot as plt
import numpy as np

data = {
    'X': [1, 2, 3, 4, 5,6,7,8,9,10],
    'Y': [5, 4, 3, 2, 1,2,3,4,5,5],
    'XL': [2,    None, 4,    None, None,None,4,5,None,3],
    'YL': [3,    None, 2,    None, None,None,5,6,None,4],
    'XR': [None, 4,    None, 1,    None,None,None,4,5,4],
    'YR': [None, 3,    None, 5,    None,None,None,3,4,4]
}

df = pd.DataFrame(data)

grey_cond = (df['XL'].isnull() | df['YL'].isnull()) & (df['XR'].isnull() | df['YR'].isnull())
red_cond = (df['XL'].notnull() & df['YL'].notnull()) & (df['XR'].isnull() | df['YR'].isnull())
blue_cond = (df['XR'].notnull() & df['YR'].notnull()) & (df['XL'].isnull() | df['YL'].isnull())
green_cond = df['XR'].notnull() & df['YR'].notnull() & df['XL'].notnull() & df['YL'].notnull()

fig, ax = plt.subplots()

# Plot X, Y
ax.plot(df['X'], df['Y'], linestyle='-', color='black')
# Grey condition (none exist)
ax.plot(df['X'][grey_cond], df['Y'][grey_cond],
    color='None',
    marker='o',
    markeredgecolor='grey',
    markerfacecolor='grey'
)
# Red condition (only XL, YL exist)
ax.plot(df['X'][red_cond], df['Y'][red_cond],
    color='None',
    marker='o',
    markeredgecolor='red',
    markerfacecolor='red'
)
# Blue condition (only XR, YR exist)
ax.plot(df['X'][blue_cond], df['Y'][blue_cond],
    color='None',
    marker='o',
    markeredgecolor='blue',
    markerfacecolor='blue'
)
# Green condition (Both exist)
ax.plot(df['X'][green_cond], df['Y'][green_cond],
    color='None',
    marker='o',
    markeredgecolor='green',
    markerfacecolor='green'
)

# Update plot settings
ax.set_title('Trajectory Plot')
ax.set_xlabel('X-axis')
ax.set_ylabel('Y-axis')

# Show the plot
plt.show()

    输出将如下所示： 输出图片

    这也没有彩色线条，但我认为这样应该更正确。否则，您必须选择要绘制与标记相同颜色的标记（数据点）的哪一侧（左侧或右侧）。

    label如果需要，您还可以通过添加到每个标记图来添加图例：

    fig, ax = plt.subplots()

# Plot X, Y
ax.plot(df['X'], df['Y'], linestyle='-', color='black',label="Trajectory")
# Grey condition (none exist)
ax.plot(df['X'][grey_cond], df['Y'][grey_cond],
    color='None',
    marker='o',
    markeredgecolor='grey',
    markerfacecolor='grey',
    label='Neither XL,YL nor XR,YR exist'
)
# Red condition (only XL, YL exist)
ax.plot(df['X'][red_cond], df['Y'][red_cond],
    color='None',
    marker='o',
    markeredgecolor='red',
    markerfacecolor='red',
    label='Only XL,YL exist'
)
# Blue condition (only XR, YR exist)
ax.plot(df['X'][blue_cond], df['Y'][blue_cond],
    color='None',
    marker='o',
    markeredgecolor='blue',
    markerfacecolor='blue',
    label='Only XR,YR exist'
)
# Green condition (Both exist)
ax.plot(df['X'][green_cond], df['Y'][green_cond],
    color='None',
    marker='o',
    markeredgecolor='green',
    markerfacecolor='green',
    label='Both XL,YL and XR,YR exist'
)

# Update plot settings
ax.set_title('Trajectory Plot')
ax.set_xlabel('X-axis')
ax.set_ylabel('Y-axis')
plt.legend()
plt.show()

    带有图例的输出将如下所示： 带图例的输出图

    希望这是有道理的

    干杯达维德

    • 0

相关问题