Notes about how to optimize R codes.
- [Forget
forLoops](#ForgetforLoops)
Nested for Loops
As for loops in R are extremly slow, it is better to wrap the process into a nested sapply function.
Note: To update a global vairable inside a function, use <<-.
# nested for loop
for(i in seq(0.1, 1, 0.1)){
for(j in seq(1, 10, 1)){
function(i, j) # any function with parameter i and j
}
}
# improved version, nested sapply loop
sapply(seq(0.1, 1, 0.1), function(i)
sapply(seq(1, 10, 1), function(j)
function(i, j)))