Dear all,
I am wondering if there is a minor bug in the optimimize function; please see below:
---
## example taken from optimize documentation
f <- function (x, a) (x - a)^2
xmin <- optimize(f, c(0, 1), tol = 0.0001, a = 1/3)
xmin
$minimum
[1] 0.3333333
$objective
[1] 0
## if we change argument a to j things still work fine
f2 <- function (x, j) (x - j)^2
xmin2 <- optimize(f2, c(0, 1), tol = 0.0001, j = 1/3)
xmin2
$minimum
[1] 0.3333333
$objective
[1] 0
## if we change argument a to i things fail
f3 <- function (x, i) (x - i)^2
xmin3 <- optimize(f3, c(0, 1), tol = 0.0001, i = 1/3)
Error in optimize(f3, c(0, 1), tol = 1e-04, i = 1/3) :
'xmin' not less than 'xmax'
xmin3
$minimum
[1] 0.3333333
$objective
[1] 0
##Same here
xmin3 <- optimize(f3, lower=0, upper=1, tol = 0.0001, i = 1/3)
Error in f(arg, ...) (from #1) : argument "i" is missing, with no default
xmin3
$minimum
[1] 0.3333333
$objective
[1] 0
## a workaround is
xmin3 <- optimize(f3, interval=c(0, 1), tol = 0.0001, i = 1/3)
xmin3
$minimum
[1] 0.3333333
$objective
[1] 0
---
the problem is, I guess, due to the keyword 'interval' gets mixed
up with 'i'.
Has anyone experienced that?
Best regards
S?ren