Displaying 20 results from an estimated 20000 matches similar to: "Efficient swapping"
2017 Jul 06
3
Efficient swapping
Thanks a lot, Ista! I really appreciate it.
How about a slightly different case as the following:
set.seed(1)
(tmp <- data.frame(x = 1:10, R1 = sample(LETTERS[1:5], 10, replace =
TRUE), R2 = sample(LETTERS[2:6], 10, replace = TRUE)))
x R1 R2
1 C B
2 B B
3 C E
4 E C
5 E B
6 D E
7 E E
8 D F
9 C D
10 A E
Notice that the factor levels between
2017 Jul 06
0
Efficient swapping
Untested, but I expect that setting the levels to be the same across the
two factors
levels(tmp$R1) <- levels(tmp$R2) <- LETTERS[1:6]
and proceeding as before should be fine.
Best,
Ista
On Jul 6, 2017 6:54 PM, "Gang Chen" <gangchen6 at gmail.com> wrote:
Thanks a lot, Ista! I really appreciate it.
How about a slightly different case as the following:
set.seed(1)
(tmp
2017 Jul 06
0
Efficient swapping
How about
foo <- with(list(r1 = tmp$R1,
r2 = tmp$R2,
swapme = (as.numeric(tmp$R1) - as.numeric(tmp$R2)) %% 2 != 0),
{
tmp[swapme, "R1"] <- r2[swapme]
tmp[swapme, "R2"] <- r1[swapme]
tmp
})
Best,
Ista
On Thu, Jul 6, 2017 at 4:06 PM, Gang Chen <gangchen6 at gmail.com> wrote:
> Suppose that we have the following
2009 Jan 06
5
Using apply for two datasets
I can run one-sample t-test on an array, for example a matrix myData1,
with the following
apply(myData1, 2, t.test)
Is there a similar fashion using apply() or something else to run
2-sample t-test with datasets from two groups, myData1 and myData2,
without looping?
TIA,
Gang
2005 Apr 28
3
have to point it out again: a distribution question
Stock returns and other financial data have often found to be heavy-tailed.
Even Cauchy distributions (without even a first absolute moment) have been
entertained as models.
Your qq function subtracts numbers on the scale of a normal (0,1)
distribution from the input data. When the input data are scaled so that
they are insignificant compared to 1, say, then you get essentially the
2011 Mar 10
3
A question about data frame
A very simple question. With a data frame like this:
> n = c(2, 3, 5)
> s = c("aa", "bb", "cc")
> df = data.frame(n, s)
I want df$s[1] or df[1,2], but how can I get rid of the extra line in
the output about the factor levels:
> df$s[1]
[1] aa
Levels: aa bb cc
Thanks,
Gang
2012 Feb 07
6
Setting up infile for R CMD BATCH
Suppose I create an R program called myTest.R with only one line like
the following:
type <- as.integer(readline("input type (1: type1; 2: type2)? "))
Then I'd like to run myTest.R in batch mode by constructing an input
file called answers.R with the following:
source("myTest.R")
1
When I ran the following at the terminal:
R CMD BATCH answer.R output.Rout
it failed
2010 Mar 27
3
Calculate variance/covariance with complex numbers
Anybody knows what functions can be used to calculate
variance/covariance with complex numbers? var and cov don't seem to
work:
> a
1
V1 0.00810014+0.00169366i
V2 0.00813054+0.00158251i
V3 0.00805489+0.00163295i
V4 0.00809141+0.00159533i
V5 0.00813976+0.00161850i
> var(a)
1
1 1.141556e-09
Warning message:
In var(a) : imaginary parts discarded in
2013 Dec 14
2
Change factor levels
Suppose I have a dataframe 'd' defined as
L3 <- LETTERS[1:3]
d0 <- data.frame(cbind(x = 1, y = 1:10), fac = sample(L3, 10, replace
= TRUE))
(d <- d0[d0$fac %in% c('A', 'B'),])
x y fac
2 1 2 B
3 1 3 A
4 1 4 A
5 1 5 A
6 1 6 B
8 1 8 A
Even though factor 'fac' in 'd' only has 2 levels, but it seems to bear the
birthmark
2010 Feb 05
3
metafor package: effect sizes are not fully independent
In a classical meta analysis model y_i = X_i * beta_i + e_i, data
{y_i} are assumed to be independent effect sizes. However, I'm
encountering the following two scenarios:
(1) Each source has multiple effect sizes, thus {y_i} are not fully
independent with each other.
(2) Each source has multiple effect sizes, each of the effect size
from a source can be categorized as one of a factor levels
2008 Apr 07
3
Extract values from a named array
Sorry for this dumb question. Suppose I have a named array ww defined as
ww <- 1:5
names(ww) <- c("a", "b", "c", "d", "e")
How can I extract the whole array of numbers without the names?
ww[1:5] does not work while ww[[1]] can only extract one number at a
time.
Thanks,
Gang
2011 Jan 21
11
[PATCH]x86:x2apic: Disable x2apic on x86-32 permanently
x86:x2apic: Disable x2apic on x86-32 permanently
x2apic initialization on x86_32 uses vcpu pointer before it is initialized. As x2apic is unlikely to be used on x86_32, this patch disables x2apic permanently on x86_32. It also asserts the sanity of vcpu pointer before dereference to prevent further misuse.
Signed-off-by: Fengzhe Zhang <fengzhe.zhang@intel.com>
diff -r 02c0af2bf280
2008 Mar 06
2
Array arithmetic
I have two arrays A and B with dimensions of (L, M, N, P) and (L, M,
N), and I want to do
for (i in 1:L) {
for (j in 1:M) {
for (k in 1:N) {
if (abs(B[i, j, k]) > 10e-5) C[i, j, k,] <- A[i, j, k,]/B[i, j, k]
else C[i, j, k,] <- 0
}
}
}
How can I get C more efficiently than looping?
Thanks,
Gang
2013 Oct 09
2
[LLVMdev] Question about anti-dependence breaker
hi,
I have few question about breaking anti-dependence of postRAScheduler in LLVM.
when I use command line "clang -target arm -mcpu=cortex-a8 -O2 -integrated-as -c test.c -o test.o"
and get objdump file as follows:
ldrr1, [r0,#16]----(1
str r1, [r0,#32]----(2
ldr r1, [r0,#12]----(3
str r1, [r0,#36]----(4
ldr r1, [r0,#08]----(5
str r1, [r0,#40]----(6
However, I expect that instruction
2011 May 22
2
Convert dataframe with two factors from wide to long format
I know how to convert a simple dataframe from wide to long format with one
varying factor. However, for a dataset with two factors like the following,
Subj T1_Cond1 T1_Cond2 T2_Cond1 T2_Cond2
1 0.125869 4.108232 1.099392 5.556614
2 1.427940 2.170026 0.120748 1.176353
How to elegantly convert to a long form as
Subj Time Cond Value
1 1 1 0.125869
1
2013 Oct 09
0
[LLVMdev] Question about anti-dependence breaker
----- Original Message -----
>
>
>
> hi,
> I have few question about breaking anti-dependence of postRAScheduler
> in LLVM.
> when I use command line "clang -target arm -mcpu=cortex-a8 -O2
> -integrated-as -c test.c -o test.o"
> and get objdump file as follows:
> ldr r1, [r0,#16]----(1
> str r1, [r0,#32]----(2
> ldr r1, [r0,#12]----(3
> str r1,
2003 Mar 06
1
Virtual servers for 2 workgroup
Hi
My config: Samba 2.2.3 & Linux Debian Testing kernel 2.4.20
There are two network cards on my pc :
-one links to the network R1 (138.231.121.12)
-one links to the network R2 (192.168.0.1)
I would like to open two shares:
-the first one on R1 in the workgroup wkgrp1
-the second one on R2 in the workgroup wkgrp2
I read that, thanks to the directives "netbios
2010 Feb 15
2
[LLVMdev] Incorrect execution of global constructor with JIT on ARM
Hello, llvm developers!
I am running LLVM with JIT on ARM. For simple programs it runs ok, but for lager code I have stumbled upon some issues.
See following C++ code to which I have reduced the problem:
#include <stdio.h>
struct Global {
typedef unsigned char ArrayType[4];
ArrayType value;
Global(const ArrayType& arg) {
for (int i = 0; i < 4; i++) this->value[i] =
2010 Feb 17
0
[LLVMdev] Incorrect execution of global constructor with JIT on ARM
On 15 February 2010 14:49, Martins Mozeiko <49640f8a at gmail.com> wrote:
> #include <stdio.h>
> struct Global {
> typedef unsigned char ArrayType[4];
> ArrayType value;
> Global(const ArrayType& arg) {
> for (int i = 0; i < 4; i++) this->value[i] = arg[i];
> }
> };
> static const unsigned char arr[] = { 1, 2, 3, 4 };
> static const Global
2018 Feb 20
3
Take the maximum of every 12 columns
This is what I was looking for. Thank you everyone!
Sincerely,
Milu
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