按R中的因子筛选数据帧

我有以下数据帧：

sp <- combn(c("sp1","sp2","sp3","sp4"),2)
d <- data.frame(t(sp),"freq"=sample(0:100,6))

我试过：

sub <- d[d$X1 == x1 & d$X2 == x2,]

关于如何解决这个问题，你有什么想法吗？

你差不多做到了：

d[d$X1 %in% x1 & d$X2 %in% x2,]

---

不要将

x1

和

x2

作为因素。只需使用向量。使用%中的

%进行逻辑测试

sp <- combn(c("sp1","sp2","sp3","sp4"),2)
d <- data.frame(t(sp),"freq"=sample(0:100,6))
x1 <- c("sp1","sp2")
x2 <- c("sp3","sp4")
sub <- d[d$X1 %in% x1 & d$X2 %in% x2,]

sp
Error in Ops.factor(d$X1, x1) : level sets of factors are different

d[d$X1 %in% x1 & d$X2 %in% x2,]

sp <- combn(c("sp1","sp2","sp3","sp4"),2)
d <- data.frame(t(sp),"freq"=sample(0:100,6))
x1 <- c("sp1","sp2")
x2 <- c("sp3","sp4")
sub <- d[d$X1 %in% x1 & d$X2 %in% x2,]