HI,
2-0.7==0.3
#[1] FALSE
##May be u meant
?2-0.7==1.3
#[1] TRUE
Possibly R FAQ 7.31
Also, check
http://rwiki.sciviews.org/doku.php?id=misc:r_accuracy
all.equal(2-0.7,1.3)
#[1] TRUE
?all.equal(1-0.7,0.3)
#[1] TRUE
(1-0.7)<(0.3+.Machine$double.eps^0.5)
#[1] TRUE
?p <- c(0.2, 0.4, 0.6, 0.8, 1)
round((1-p)*5,1)+1
#[1] 5 4 3 2 1
In your second example,
?p <- c(0.8, 0.6, 0.4, 0.2, 0)
floor((1 - p) * 5) + 1
#[1] 1 3 4 5 6?
((1-0.8)*5) +1
#[1] 2
?round((1-p)*5,1)+1
#[1] 2 3 4 5 6
A.K.
...is false :( However (2 - 0.7) == 0.3 is true.
Is there any way to get around this? ?
The end goal is for this to work:
p <- c(0.2, 0.4, 0.6, 0.8, 1)
floor((1 - p) * 5) + 1
> ?5 4 3 1 1
whereas the correct result would have been 5 4 3 2 1. If I set p <- c(0.8,
0.6, 0.4, 0.2, 0) then it works as expected.