Displaying 20 results from an estimated 10000 matches similar to: "sequence()"
2005 Jun 29
6
x*x*x*... vs x^n
Hi
I have been wondering if there one can speed up calculating small powers
of numbers such as x^8 using multiplication.
In addition, one can be a bit clever and calculate x^8 using only 3
multiplies.
look at this:
> f1 <- function(x){x*x*x*x*x*x*x*x}
> f2 <- function(x){x^8}
> f3 <- function(x){x2 <- x*x;x4 <- x2*x2;return(x4*x4)}
[so f1() and f2() and f3() are
2009 Oct 20
1
[LLVMdev] 2.6 pre-release2 ready for testing
G'Day Tanya,
Is it too late to bring in the following patches to fix some major
brokenness in the AuroraUX tool chain for 2.6?
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?r1=84468&r2=84469&view=diff&pathrev=84469
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?r1=84265&r2=84266&view=diff&pathrev=84266
2006 Nov 15
3
how to get empty sequence for certain bounds
Hi,
I have encountered this problem quite a few times and thought I would
ask.
Let's say that I have two endpoints, a and b, which are integers. If
a <= b, I would like to get a:b, but if a > b, then numeric(0), for
example:
myseq(3,5) => 3:5
myseq(3,3) => 3
myseq(3,2) => numeric(0)
The operator : just gives decreasing sequences in the latter case, and
I could not coax seq
2013 Mar 06
3
About basic logical operators
Hello everyone,
I have a basic question regarding logical operators.
> x<-seq(-1,1,by=0.02)
> x
[1] -1.00 -0.98 -0.96 -0.94 -0.92 -0.90 -0.88 -0.86 -0.84 -0.82 -0.80 -0.78
[13] -0.76 -0.74 -0.72 -0.70 -0.68 -0.66 -0.64 -0.62 -0.60 -0.58 -0.56 -0.54
[25] -0.52 -0.50 -0.48 -0.46 -0.44 -0.42 -0.40 -0.38 -0.36 -0.34 -0.32 -0.30
[37] -0.28 -0.26 -0.24 -0.22 -0.20 -0.18 -0.16
2011 Jan 21
4
clustering fuzzy
hello,
i'm pete ,how can i order rows of matrix by max to min value?
I have a matrix of membership degrees, with 82 (i) rows and K coloumns, K
are clusters.
I need first and second largest elements of the i-th row.
for example
1 0.66 0.04 0.01 0.30
2 0.02 0.89 0.09 0.00
3 0.06 0.92 0.01 0.01
4 0.07 0.71 0.21 0.01
5 0.10 0.85 0.04 0.01
6 0.91 0.04 0.02 0.02
7 0.00 0.01 0.98 0.00
8 0.02
2010 Feb 17
2
extract the data that match
Hi r-users,
I would like to extract the data that match. Attached is my data:
I'm interested in matchind the value in column 'intg' with value in column 'rand_no'
> cbind(z=z,intg=dd,rand_no = rr)
z intg rand_no
[1,] 0.00 0.000 0.001
[2,] 0.01 0.000 0.002
[3,] 0.02 0.000 0.002
[4,] 0.03 0.000 0.003
[5,] 0.04 0.000 0.003
[6,]
2005 Oct 05
2
eliminate t() and %*% using crossprod() and solve(A,b)
Hi
I have a square matrix Ainv of size N-by-N where N ~ 1000
I have a rectangular matrix H of size N by n where n ~ 4.
I have a vector d of length N.
I need X = solve(t(H) %*% Ainv %*% H) %*% t(H) %*% Ainv %*% d
and
H %*% X.
It is possible to rewrite X in the recommended crossprod way:
X <- solve(quad.form(Ainv, H), crossprod(crossprod(Ainv, H), d))
where quad.form() is a little
2004 Oct 06
3
crossprod vs %*% timing
Hi
the manpage says that crossprod(x,y) is formally equivalent to, but
faster than, the call 't(x) %*% y'.
I have a vector 'a' and a matrix 'A', and need to evaluate 't(a) %*% A
%*% a' many many times, and performance is becoming crucial. With
f1 <- function(a,X){ ignore <- t(a) %*% X %*% a }
f2 <- function(a,X){ ignore <-
2010 Mar 31
1
Weird R behaviour?
Dear list,
I have observed a weird behaviour from R --- apologies if I am missing
something obvious!
df3f826f28
df3f826f28
Say you type in R:
>c.preec <- 10074
>c.gd <- 2200
>p1 <- .2
>c.neo <- p1*9451 + (1-p1)*3883
>n.preec <- 3710
>n.gd <- 2650
>n.neo <- 2120
>n.pcos <- 53000
>unit.met <- 94
>cost.met <- 94*n.pcos
>effect <-
2013 May 15
1
x and y lengths differ
I have a problem with R. I try to compute the confidence interval for my
df. When I want to create the plot I have this problem: Error in
xy.coords(x, y, xlabel, ylabel, log) : 'x' and 'y' lengths differ.
I try this code:
library(dplR)
df.rwi <- detrend(rwl = df, method = "Spline",nyrs=NULL)
write.table(df.rwi,file="rwi.txt",quote=FALSE,row.names=TRUE)
2008 Jan 28
0
[LLVMdev] 2.2 Prerelease available for testing
Target: FreeBSD 7.0-RC1 on amd64.
autoconf says:
configure:2122: checking build system type
configure:2140: result: x86_64-unknown-freebsd7.0
[...]
configure:2721: gcc -v >&5
Using built-in specs.
Target: amd64-undermydesk-freebsd
Configured with: FreeBSD/amd64 system compiler
Thread model: posix
gcc version 4.2.1 20070719 [FreeBSD]
[...]
objdir != srcdir, for both llvm and gcc.
Release
2008 Jan 24
6
[LLVMdev] 2.2 Prerelease available for testing
LLVMers,
The 2.2 prerelease is now available for testing:
http://llvm.org/prereleases/2.2/
If anyone can help test this release, I ask that you do the following:
1) Build llvm and llvm-gcc (or use a binary). You may build release
(default) or debug. You may pick llvm-gcc-4.0, llvm-gcc-4.2, or both.
2) Run 'make check'.
3) In llvm-test, run 'make TEST=nightly report'.
4) When
2009 Oct 06
2
ggplot cumsum refined question (?)
OK, so maybe last night was a little too much at one throw, so I have
reduced the data to two stations- one that has precipitation and one
that does not. This is going to be in the context of a larger data
set. I would like to be able to issue a ggplot command and have cum
sum just act on the facets (factors) to apply this.
library(chron)
library(ggplot2)
DF <- structure(list(date_time =
2007 Sep 18
0
[LLVMdev] 2.1 Pre-Release Available (testers needed)
Hi,
LLVM 2.1-pre1 test results:
Linux (SUSE) on x86 (P4)
Release mode, but with assertions enabled
LLVM srcdir == objdir
# of expected passes 2250
# of expected failures 5
I ran the llvm-test suite on my desktop while I was also working on that PC,
so don't put too much trust in the timing info. Especially during the "spiff"
test the machine was swapping
2009 Oct 20
0
[LLVMdev] 2.6 pre-release2 ready for testing
Hi Tanya,
> 1) Compile llvm from source and untar the llvm-test in the projects
> directory (name it llvm-test or test-suite). Choose to use a
> pre-compiled llvm-gcc or re-compile it yourself.
I compiled llvm and llvm-gcc with separate objects directories.
Platform is x86_64-linux-gnu.
> 2) Run make check, report any failures (FAIL or unexpected pass). Note
> that you need to
2009 Oct 20
1
[LLVMdev] 2.6 pre-release2 ready for testing
On Oct 20, 2009, at 6:02 AM, Duncan Sands wrote:
> Hi Tanya,
>
>> 1) Compile llvm from source and untar the llvm-test in the projects
>> directory (name it llvm-test or test-suite). Choose to use a pre-
>> compiled llvm-gcc or re-compile it yourself.
>
> I compiled llvm and llvm-gcc with separate objects directories.
> Platform is x86_64-linux-gnu.
>
Ok.
2016 May 27
2
Slow RAID Check/high %iowait during check after updgrade from CentOS 6.5 -> CentOS 7.2
All of our Kafka clusters are fairly write-heavy. The cluster in question is our second-heaviest ? we haven?t yet upgraded the heaviest, due to the issues we?ve been experiencing in this one.
Here is an iostat example from a host within the same cluster, but without the RAID check running:
[root at r2k1 ~] # iostat -xdmc 1 10
Linux 3.10.0-327.13.1.el7.x86_64 (r2k1) 05/27/16 _x86_64_ (32 CPU)
2012 Oct 06
3
vector is not assigned correctly in for loop
Hi there,
Here is a minimum working example:
----------------------------------------------------------------
lower = 0
upper = 1
n_bins = 50
interval = (upper - lower) / n_bins
bins = vector(mode="numeric", length=n_bins)
breaks = seq(from=lower + interval, to=upper, by=interval)
for(idx in breaks)
{
bins[idx / interval] = idx
}
print(bins)
2007 Apr 11
1
Programming Problem (for loop, random # control, 3 dimentional graph)
Dear List,
This is just a programming problem which i cannot seem
to figure out. I am trying to get a set of power from
a test (say, kolmogorov smirnov) out of a distribution
(say, G-K distribution) as follows. I am trying to
reduce to pain of writing the whole set of data points
(p# below) using "for" loop. However, I seem to have
some problem in it as the output "M" does not
2008 Dec 06
1
Morlet wavelet not supportd by wavCWTPeaks
aa <- (structure(list(X.0.85 = c(-1.02, -1.17, -1.29, -1.39, -1.46,
-1.5, -1.52, -1.5, -1.46, -1.39, -1.3, -1.19, -1.07, -0.93, -0.79,
-0.65, -0.5, -0.36, -0.22, -0.08, 0.05, 0.18, 0.3, 0.41, 0.52,
0.62, 0.72, 0.81, 0.89, 0.98, 1.05, 1.13, 1.19, 1.25, 1.29, 1.31,
1.31, 1.29, 1.24, 1.16, 1.06, 0.93, 0.77, 0.58, 0.38, 0.16, -0.07,
-0.31, -0.89, -1.05, -1.19, -1.31, -1.41, -1.47, -1.51, -1.51,