python中如何畫火山圖

1、導(dǎo)入數(shù)據(jù)

importpandasaspd#Dataanalysis

importnumpyasnp#Scientificcomputing

importseabornassns#Statisticalvisualization

#讀取數(shù)據(jù)

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、設(shè)置閾值

#設(shè)置pvalue和logFC的閾值

cut_off_pvalue=0.0000001

cut_off_logFC=1

3、設(shè)置分組

#分組為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、繪制散點圖

#繪制散點圖

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、設(shè)置散點圖

#確定坐標(biāo)軸顯示范圍

xmin=-6

xmax=10

ymin=7

ymax=13

ax.spines['right'].set_visible(False)#去掉右邊框

ax.spines['top'].set_visible(False)#去掉上邊框

ax.vlines(-cut_off_logFC,ymin,ymax,color='dimgrey',linestyle='dashed',linewidth=1)#畫豎直線

ax.vlines(cut_off_logFC,ymin,ymax,color='dimgrey',linestyle='dashed',linewidth=1)#畫豎直線

ax.hlines(-np.log10(cut_off_pvalue),xmin,xmax,color='dimgrey',linestyle='dashed',linewidth=1)#畫豎水平線

ax.set_xticks(range(xmin,xmax,4))#設(shè)置x軸刻度

ax.set_yticks(range(ymin,ymax,2))#設(shè)置y軸刻度

ax.set_ylabel('-log10(pvalue)',fontweight='bold')#設(shè)置y軸標(biāo)簽

ax.set_xlabel('log2(foldchange)',fontweight='bold')#設(shè)置x軸標(biāo)簽

以上就是python中畫火山圖的方法，希望能對大家有所幫助，更多Python學(xué)習(xí)教程請關(guān)注IT培訓(xùn)機構(gòu):千鋒教育。