Instant vectorization in R is a feature that allows you to write vectorized code that is more efficient and concise. It does this by automatically vectorizing certain operations, even if they are not explicitly vectorized.
For example, the following code:
x <- 1:10
y <- 2:11
z <- x + y
Is automatically vectorized by Instant vectorization. This means that the addition operation is performed in parallel on the elements of x and y, and the result is stored in z. This is much more efficient than the following code, which manually vectorizes the addition operation:
z <- numeric(10)
for (i in 1:10) {
z[i] <- x[i] + y[i]
}
Instant vectorization can also be used to improve the performance of more complex operations. For example, the following code:
x <- matrix(1:100, 10, 10)
y <- matrix(2:101, 10, 10)
z <- x + y
Is automatically vectorized by Instant vectorization. This means that the addition operation is performed in parallel on the elements of x and y, and the result is stored in z. This is much more efficient than the following code, which manually vectorizes the addition operation:
z <- matrix(0, 10, 10)
for (i in 1:10) {
for (j in 1:10) {
z[i, j] <- x[i, j] + y[i, j]
}
}
To use Instant vectorization, you need to enable it in your R session. You can do this by setting the `options(vectorize.instant=TRUE)`. Once you have enabled Instant vectorization, you can start writing vectorized code.
Note
- Use vectorized functions whenever possible.
- Avoid using loops in vectorized code.
- Use the `%*%` operator for matrix multiplication.
- Use the `apply()` function for more complex operations.
