Let’s look at an example of usingget(). Say we have two matrices,uand
v, containing statistical data, and we wish to apply R’s linear regression func-
tionlm()to each of them.
u
[,1] [,2]
[1,] 1 1
[2,] 2 2
[3,] 3 4
v
[,1] [,2]
[1,] 8 15
[2,] 12 10
[3,] 20 2
for (m in c("u","v")) {
- z <- get(m)
- print(lm(z[,2] ~ z[,1]))
+}
Call:
lm(formula = z[, 2] ~ z[, 1])
Coefficients:
(Intercept) z[, 1]
-0.6667 1.5000
Call:
lm(formula = z[, 2] ~ z[, 1])
Coefficients:
(Intercept) z[, 1]
23.286 -1.071
Here,mwas first set tou. Then these lines assign the matrixutoz, which
allows the call tolm()onu:
z <- get(m)
print(lm(z[,2] ~ z[,1]))
The same then occurs withv.7.1.3 if-else..........................................................
The syntax forif-elselooks like this:
if (r == 4) {
x<-1
R Programming Structures 143