Fastest way of finding if any members of vector x fall in the range of the rows of matrix y

require(sqldf)
x

y

sqldf("

Thanks a lot. That solves the problem :)
best,
salih

On Sat, Jun 25, 2011 at 9:13 AM, Dimitris Rizopoulos <
d.rizopoulos at erasmusmc.nl> wrote:

yet another solution is:


v <- c(1, 2, 6, 5)
w <- matrix(c(1, 4, 3, 5, 8, 10), ncol = 2, byrow = TRUE)

check <- outer(w[, 1], v, "-") * outer(w[, 2], v, "-")
v[which(check <= 0, arr.ind = TRUE)[, 2]]


Best,
Dimitris



On 6/24/2011 10:05 PM, Martin Morgan wrote:

On 06/24/2011 11:12 AM, Dennis Murphy wrote:

Hi:

Not much different from Peter's approach, but here's another try:

v<- c(1, 2, 6, 5)
w<- matrix(c(1, 4, 3, 5, 8, 10), ncol = 2, byrow = TRUE)

w

[,1] [,2]
[1,] 1 4
[2,] 3 5
[3,] 8 10


f<- function(x) v[which(v>= x[1]& v<= x[2])]
unlist(apply(w, 1, f))
[1] 1 2 5

If you just do the apply() part, the function will return a list of
those elements of v that fall within the i-th interval.

Maybe

?> v = c(1, 2, 6, 5)
?> start = c(-Inf, 1, 3, 8)
?> end = c(-Inf, 4, 5, 10)
?> v[ v <= end[findInterval(v, start)] ]

Also IRanges::findOverlaps / countOverlaps in Bioconductor

v[countOverlaps(IRanges(v, v), IRanges(start, end)) != 0]

http://bioconductor.org/**install <http://bioconductor.org/install>

Martin

HTH,
Dennis

On Fri, Jun 24, 2011 at 9:52 AM, Salih Tuna<salihtuna at gmail.com> wrote:

Hi guys,

let's assume i have the following

1
x = 2
6
5

1 4
y = 3 5
8 10

i want the code to report back 1, 2 and 5 from x.
Basically it shopuld check whether each elements of x falls in the
range of
each row of x. 1 and 2 falls in between 1-4 and 5 falls in between 3-5.
I do this with two for loops but in the case of very large list, it
takes
ages.

best,
salih


On Fri, Jun 24, 2011 at 4:12 PM, Dennis Murphy<djmuser at gmail.com>
wrote:

Hi:

That leaves open several possibilities. Could you please supply a
small, reproducible example (i.e., one that someone can copy and paste
into an R session) that illustrates the problem along with the
solution you expect?

TIA,
Dennis

On Fri, Jun 24, 2011 at 2:30 AM, Salih Tuna<salihtuna at gmail.com>
wrote:

Hi Dimitris,
Thanks for your reply. But this is not exactly what i am after. I want
to
find the probes that falls into certain regions. In your solution it
will
ignore the second probe if it falls into the same region as the first
one.
Is there any vector trickb uilt in R to find whether probes fall into
certain regions?
best,
salih

On Fri, Jun 24, 2011 at 10:23 AM, Dimitris Rizopoulos<
d.rizopoulos at erasmusmc.nl> wrote:

One approach is the following:

x<- rnorm(5)
y<- matrix(rnorm(5*2), 5, 2)

check<- y - x
check[, 1] * check[, 2]< 0


I hope it helps.

Best,
Dimitris



On 6/24/2011 10:57 AM, Salih Tuna wrote:

Hi All,

What is the fastest way of finding if any members of vector x
fall in
the
range of the rows of matrix y?
I do not want to use two for loops as this will take forever.
Any help will be appreciated,
best,
salih

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Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014
Web:
http://www.erasmusmc.nl/****biostatistiek/<http://www.erasmusmc.nl/**biostatistiek/>
<http://www.**erasmusmc.nl/biostatistiek/<http://www.erasmusmc.nl/biostatistiek/>

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--
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014
Web: http://www.erasmusmc.nl/**biostatistiek/<http://www.erasmusmc.nl/biostatistiek/>

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