CODEWITHSUNDEEP
r
maximus
maximus

Reputation: 11524

Different results with "same" code

I am asking a simple question. Why are these two code fragments not the same?

pNl <- {}

for(i in length(x):length(x)-250) { 
    temp <-x[i] - x[i-1] 
    pNl <-append(pNl, temp, length(pNl))
}

pNl

and

PnL <- {}

for(i in length(x):(length(x)-250)) {
    temp <- x[i] - x[i-1]
    PnL <- append(PnL, temp, length(PnL))
}


PnL

I get different results when I execute them...

I really appreciate your answer!!!

Upvotes: 0

Views: 315

Answers (1)

csgillespie
csgillespie

Reputation: 60452

The problem is in the for loop definition. In the first loop statement you have left off brackets, i.e.

#length(x):length(x)-250
R> 2:5-1
[1] 1 2 3 4

In the second loop you have brackets, so:

#length(x):(length(x)-250) 
R> 2:(5-1)
[1] 2 3 4

These two statements are not the same and so you are not looping over the same thing.

Upvotes: 6

Related Questions