使用Python，matplotlib绘制Nomogram列线图

这篇博客将介绍如何使用Python，matplotlib绘制列线图。写这篇博客源于博友的提问

期望使用matplotlib绘制列线图如下，翻官网文档，尝试后终于绘制出来了。

1. 效果图

2. 源码

# 绘制列线图

import matplotlib.pyplot as plt
from matplotlib import ticker
import matplotlib

# 注意注释掉此句，才可以plt.show()看到效果图
# 设置此才可保存图片到本地，plt.savefig将保存结果图，但同时plt.show()将不在起作用
# matplotlib.use("Agg")

# 设置展示的刻度
# 设置刻度轴位置
# 刻度起始值、结束值、刻度最小精度、刻度间隔
# 文字位置
def setup(ax, title, minx, maxx, major, minor, position="bottom"):
    # 只显示底部脊椎
    ax.yaxis.set_major_locator(ticker.NullLocator())
    ax.spines['right'].set_color('none')
    ax.spines['left'].set_color('none')
    if (position == "bottom"):
        ax.spines['top'].set_color('none')
    elif (position == "top"):
        ax.spines['bottom'].set_color('none')

    # 定义刻度最大最小精度
    ax.xaxis.set_major_locator(ticker.MultipleLocator(major))
    ax.xaxis.set_minor_locator(ticker.MultipleLocator(minor))  # 最小刻度精度

    # 定义刻度位置
    ax.xaxis.set_ticks_position(position)

    ax.set_xlim(minx, maxx)
    ax.text(-0.5, -0.3, title, transform=ax.transAxes,
            fontsize=9, fontname='Monospace', color='black')


fig, axs = plt.subplots(9, 1, figsize=(8, 6))
# fig.suptitle("Nomogram demo") # 设置标题

setup(axs[0], title="Points", position="top", minx=0, maxx=100, major=10, minor=2.5)
axs[0].xaxis.set_major_formatter(ticker.ScalarFormatter(useMathText=True))

setup(axs[1], title="Age", minx=35, maxx=85, major=5, minor=5)
axs[1].xaxis.set_major_formatter(ticker.ScalarFormatter(useMathText=True))

setup(axs[2], title="Blood Glucose", minx=100, maxx=50, major=10, minor=10)
axs[2].xaxis.set_major_formatter(ticker.ScalarFormatter(useMathText=True))

setup(axs[3], title="Gender", minx=1, maxx=0, major=1, minor=1)
axs[3].xaxis.set_major_formatter(ticker.ScalarFormatter(useMathText=True))

setup(axs[4], title="TotalPoints", minx=0, maxx=260, major=20, minor=4)
axs[4].xaxis.set_major_formatter(ticker.ScalarFormatter(useMathText=True))

setup(axs[5], title="Linear Predictor", minx=-0.8, maxx=0.8, major=0.2, minor=0.1)
axs[5].xaxis.set_major_formatter(ticker.ScalarFormatter(useMathText=True))

setup(axs[6], title="1-yearSurvival Probability", minx=0.85, maxx=0.5, major=0.05, minor=0.05)
axs[6].xaxis.set_major_formatter(ticker.ScalarFormatter(useMathText=True))

setup(axs[7], title="3-yearSurvival Probability", minx=0.5, maxx=0.05, major=0.05, minor=0.05)
axs[7].xaxis.set_major_formatter(ticker.ScalarFormatter(useMathText=True))

setup(axs[8], title="5-yearSurvival Probability", minx=0.25, maxx=0.05, major=0.05, minor=0.05)
axs[8].xaxis.set_major_formatter(ticker.ScalarFormatter(useMathText=True))
fig.tight_layout()
plt.show()

# 保存图片
# plt.savefig('nomogram.jpg')

参考

• https://matplotlib.org/stable/gallery/ticks_and_spines/tick-formatters.html#sphx-glr-gallery-ticks-and-spines-tick-formatters-py
• https://matplotlib.org/stable/gallery/ticks_and_spines/tick-locators.html#sphx-glr-gallery-ticks-and-spines-tick-locators-py