<br />
tmp = read.csv("data.txt", header = FALSE, sep = "\t")<br />
y = as.vector(tmp[, 4])<br />
x1 = as.vector(tmp[, 1])<br />
x2 = as.vector(tmp[, 2])<br />
x3 = as.vector(tmp[, 3])<br />
summary(lm(y ~ x1 + x2 + x3 + x1:x2))<br />
</p>
回归学得很烂 。。。不知道肿么办 。。。