On Thu, Feb 02, 2012 at 10:00:58AM +, Jonas Hal wrote:
> The example here puzzles me. It seems like the < operator doesn't work as
> expected.
>
> > l <- 0.6
> > u <- seq(0.4, 0.7, 0.1)
> > u
> [1] 0.4 0.5 0.6 0.7
> > mygrid <- expand.grid("l" = l, "u" = u)
> > mygrid
> l u
> 1 0.6 0.4
It's likely an infelicity of floating point representations (R FAQ
7.31) but admittedly, not a case I would have expected to present
itself.
If you want it to work out as expected, try this:
l <- 0.6
u <- seq(0.4, 0.7, 0.1)
l.int <- (6L) / 10
u.int <- seq(4, 7) / 10
l < u
l.int < u.int
Michael
This is R FAQ 7.31, about machine representation of
floating point numbers.
> mygrid$u[3] - mygrid$l[3]
[1] 1.110223e-16
So
mygrid$l[3] < mygrid$u[3]
is true, though the difference is very, very small and due solely
to the limitations of computers.
Sarah
On Thu, Feb 2, 2012 at 5:00 AM, Jonas Ha
.org [mailto:r-help-boun...@r-project.org] On
> Behalf Of Jonas Hal
> Sent: Thursday, February 02, 2012 2:01 AM
> To: r-help@r-project.org
> Subject: [R] The "less than" (<) operator doesnt seem to perform as expected
>
> The example here puzzles me. It seems like the &
The example here puzzles me. It seems like the < operator doesn't work as
expected.
> l <- 0.6
> u <- seq(0.4, 0.7, 0.1)
> u
[1] 0.4 0.5 0.6 0.7
> mygrid <- expand.grid("l" = l, "u" = u)
> mygrid
l u
1 0.6 0.4
2 0.6 0.5
3 0.6 0.6
4 0.6 0.7
> mygridcollapsed <- mygrid[mygrid$l < mygrid$u, ]
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