python中如何画火山图

import pandas as pd # Data analysis

import numpy as np # Scientific computing

import seaborn as sns # Statistical visualization

# 读取数据

df = pd.read_csv('./dataset_volcano.txt', sep='\t')

result = pd.DataFrame()

result['x'] = df['logFC']

result['y'] = df['P.Value']

result['-log10(pvalue)']=-df['P.Value'].apply(np.log10)

# 设置pvalue和logFC的阈值

cut_off_pvalue = 0.0000001

cut_off_logFC = 1

#分组为up, normal, down

result.loc[(result.x> cut_off_logFC )&(result.y < cut_off_pvalue),'group'] = 'up'

result.loc[(result.x< -cut_off_logFC )&(result.y < cut_off_pvalue),'group'] = 'down'

result.loc[(result.x>=-cut_off_logFC )&(result.x<=cut_off_logFC )|(result.y >= cut_off_pvalue),'group'] = 'normal'

#绘制散点图

ax = sns.scatterplot(x="x", y="-log10(pvalue)",

                      hue='group',

                      hue_order = ('down','normal','up'),

                      palette=("#377EB8","grey","#E41A1C"),

                      alpha=0.5,

                      s=15,

#确定坐标轴显示范围

xmin=-6

xmax=10

ymin=7

ymax=13

ax.spines['right'].set_visible(False) #去掉右边框

ax.spines['top'].set_visible(False) #去掉上边框

ax.vlines(-cut_off_logFC, ymin, ymax, color='dimgrey',linestyle='dashed', linewidth=1) #画竖直线

ax.vlines(cut_off_logFC, ymin, ymax, color='dimgrey',linestyle='dashed', linewidth=1) #画竖直线

ax.hlines(-np.log10(cut_off_pvalue), xmin, xmax, color='dimgrey',linestyle='dashed', linewidth=1) #画竖水平线

ax.set_xticks(range(xmin, xmax, 4))# 设置x轴刻度

ax.set_yticks(range(ymin, ymax, 2))# 设置y轴刻度

ax.set_ylabel('-log10(pvalue)',fontweight='bold') # 设置y轴标签

ax.set_xlabel('log2(fold change)',fontweight='bold') # 设置x轴标签