I'm given a question in R language to find the 30th term of the recurrence relation x(n) = 2*x(n-1) - x(n-2)
, where x(1) = 0 and x(2) = 1
. I know the answer is 29 from mathematical deduction. But as a newbie to R, I'm slightly confused by how to make things work here. The following is my code:
loop <- function(n){
a <- 0
b <- 1
for (i in 1:30){
a <- b
b <- 2*b - a
}
return(a)
}
loop(30)
I'm returned 1 as a result, which is way off.
In case you're wondering why this looks Python-ish, I've mostly only been exposed to Python programming thus far (I'm new to programming in general). I've tried to check out all the syntax in R, but I suppose my logic is quite fixed by Python. Can someone help me out in this case? In addition, does R have any resources like PythonTutor to help visualise the code execution logic?
Thank you!
question from:
https://stackoverflow.com/questions/65872550/iteration-of-a-recurrence-solution-in-r 与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…