如何计算R图中位于标识线(x = y)之上和下面的点

Question

我试图计算在一个地块中位于标识线(x = y)下面和上面的点数。

plot(datatumor$ageChronologique, datatumor$ageMethylation, 
     xlab ="Chronological age", ylab= "DNAm age")
abline(0,1)

"ageChronologique“和"ageMethylation”是数据仓库的两个测量变量。

提前感谢

Answer 1

您可以将逻辑datatumor$ageChronologique < datatumor$ageMethylation与sum组合起来。

# above 45 degree line:
sum(datatumor$ageChronologique < datatumor$ageMethylation)
# below 45 degree line:
sum(datatumor$ageChronologique > datatumor$ageMethylation)

也许用with看上去更好看

# above 45 degree line:
with(datatumor, sum(ageChronologique < ageMethylation))

如果变量中缺少值(NAs)，则可以将na.rm=T参数包含在sum中以忽略以下内容：

sum(datatumor$ageChronologique > datatumor$ageMethylation, na.rm=T)