python如何画火山图
python中如何画火山图
1、导入数据
importpandasaspd#Dataanalysis
importnumpyasnp#Scientificcomputing
importseabornassns#Statisticalvisualization
#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)
2、设置阈值
#设置pvalue和logFC的阈值
cut_off_pvalue=0.0000001
cut_off_logFC=1
3、设置分组
#分组为up,normal,down
result.loc[(result.x>cut_off_logFC)&(result.y result.loc[(result.x<-cut_off_logFC)&(result.y result.loc[(result.x>=-cut_off_logFC)&(result.x<=cut_off_logFC)|(result.y>=cut_off_pvalue),'group']='normal' 4、绘制散点图 #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, 5、设置散点图 #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(foldchange)',fontweight='bold')#设置x轴标签 以上就是python中画火山图的方法,希望能对大家有所帮助,更多Python学习教程请关注IT培训机构:筋斗云。