search for: randomly

Displaying 20 results from an estimated 20282 matches for "randomly".

2010 Dec 23
1
Reconcile Random Samples
Is there a way to generate identical random samples using R's runif function and SAS's ranuni function? I have assigned the same seed values in both software packages, but the following results show different results. Thanks! R === > set.seed(6) > random <- runif(10) > random [1] 0.6062683 0.9376420 0.2643521 0.3800939 0.8074834 0.9780757 0.9579337 [8] 0.7627319 0.5096485
2011 May 29
1
Fitting spline using Pspline
Hey all, I seem to be having trouble fitting a spline to a large set of data using PSpline. It seems to work fine for a data set of size n=4476, but not for anything larger (say, n=4477). For example: THIS WORKS: ----------------------------- random = array(0,c(4476,2)) random[,1] = runif(4476,0,1) random[,2] = runif(4476,0,1) random = random[order(random[,1]),] plot(random[,1],random[,2])
2012 May 07
1
Repeating
Dear All, I have a codes which calculates the result of Ripley's K function of my data. I want to repeat this process 999 times. However, i am getting an error when i use the "for i in" function. Is there any way to repeat this analysis 999 times. Here are the codes i used ; data4 <- matrix(c(sample(id),data1),203,3) a <- data4[,1] random.case=data4[a==0,]
2018 Dec 28
0
[PATCH v2 nbdkit] common: Improve pseudo-random number generation.
...rn 0; diff --git a/tests/test-random.c b/tests/test-random.c index 168331c..c02fdc2 100644 --- a/tests/test-random.c +++ b/tests/test-random.c @@ -48,6 +48,8 @@ #define SIZE 1024*1024 static char data[SIZE]; +static unsigned histogram[256]; + /* After reading the whole disk above, we then read randomly selected * subsets of the disk and compare the data (it should be identical). */ @@ -98,6 +100,27 @@ main (int argc, char *argv[]) memcpy (data, rdata, SIZE); free (rdata); + /* Test that the data is sufficiently random using a simple + * histogram. This just tests for gross errors...
2018 Dec 28
2
[PATCH v2 nbdkit] common: Improve pseudo-random number generation.
v2: - Fix seeding. - Add a test that nbdkit-random-plugin is producing something which looks at least somewhat random. Rich.
2009 May 02
2
set.seed and /dev/random
Hello, In ?set.seed I notice that a seed is created from the system time. Thus if two machines were (hypothetically) running for the same time and R was started simultaneously on both, the would have the same seeds (correct?). I assume reading from /dev/random would be different for both of these machines, so my question is why not use an integer read from /dev/random to create the seed? Would
2018 Dec 28
1
[PATCH nbdkit] common: Improve pseudo-random number generation.
Currently we use non-cryptographically secure random numbers in two places, the error filter (to inject errors at random) and the random plugin. For this we have used either random_r or a home-brew-ish Linear Congruential Generator. Use of random_r is problematic on BSDs because it doesn't exist there. Use of the LCG is simply a bad choice. Replace both uses with a better quality and
2003 Oct 16
2
.Random.seed
I am writing a function for the purposes of a simulation. Due to memory problems, the function sometimes crashes. In order to get around this problem, I would like to include to be able to save the "last" seed, so I can pick up with the next run of the simulation after a "crash". I am having trouble understanding what is going on with .Random.seed! For each run of the
2010 Feb 05
2
Random number quality
Hello, I'm running R 2.10.1 on Windows Vista. I'm selecting a random sample of several hundred items out of a larger population of several thousand. I realize there is srswor() in package sampling for exactly this purpose, but as far as I can tell it uses the native PRNG which may or may not be random enough. Instead I used the random package which pulls random numbers from random.org,
2002 May 17
2
SSH 3.2.2 on Solaris 8 with /kernel/drv/random
Hi, I'm like to try a get the new release to work with Sun's new device, that can be installed with patch 112438-01. I compiled SSL attempting to point it at the random device: cd openssl-0.9.6d ./Configure solaris-sparcv7-gcc make DEVRANDOM="/kernel/drv/random" And then ran the SSH configure: ./configure --prefix=/opt/OBSDssh --with-pam --without-rsh \ --sysconfdir=/etc/ssh
2003 May 26
5
Randomness
Hi, I am very new to R and cannot seem to find how it generates random numbers. I am currently involved with a project that requires a random number generator and have developed one. I am, however, unsure of just how random it is and was wanting to compare my generator with that of R (as well as others). If anyone knows how the random numbers are generated or have any ideas on testing or
2008 Aug 20
2
Reading in a value of .Random.seed in .Rprofile
For reasons that are best known to myself [ ;-) ] I have a value of .Random.seed saved (via dput()) in a file ``.Random.seed.save''. In my .Rprofile I have the lines: .Random.seed <- dget(".Random.seed.save") Junk <- dget(".Random.seed.save") print(all.equal(.Random.seed,dget(".Random.seed.save")))
2008 Feb 13
3
Best way to reset random seed when using set.seed() in a function?
Hi, this is related to a question just raised on Bioconductor where one function sets the random seed internally but never resets it, which results in enforced down streams random samples being deterministic. What is the best way to reset the random seed when you use set.seed() within a function? Is it still to re-assign '.Random.seed' in the global environment as following example
2008 Jun 23
1
problem in R for Linear mixed model~
Dear R users: I just got confused some R code used in linear mixed model~ example,two factors,A, B,C,A is fixed ,B,C are random,and B is nested in C,if I wannt to use linear mixed model,are the following code correct for each case? case1:want to know random effect of B, case1<-lme(y~A*B*C,random=~B|C) where "B|C" stand for what?,mean B is nested in C? case2: how to wirte
2010 Nov 08
4
Random Sample
Hello R users, Here is my question about generating random sample. How to set the random seed to recreate the same random numbers? For example, 10 random numbers is generated from N(0,1), then "runif(10)" is used.What if I want to get the same 10 random numbers when I run runif(10) again? Is it possible?I think .Random.seed should be used here. Thanks. Xiaoxi [[alternative
2006 Aug 31
0
New package 'random' for non-deterministic random number
Dear useRs, A few days ago, the initial version 0.1.0 of a new package 'random' was uploaded to CRAN. The random packages provides convenient access to the non-deterministic random numbers provided by the random.org site created by Mads Haahr (http://www.random.org). While certain hardware and software solutions that provide access to non-deterministic random-numbers exist, few if any
2006 Aug 31
0
New package 'random' for non-deterministic random number
Dear useRs, A few days ago, the initial version 0.1.0 of a new package 'random' was uploaded to CRAN. The random packages provides convenient access to the non-deterministic random numbers provided by the random.org site created by Mads Haahr (http://www.random.org). While certain hardware and software solutions that provide access to non-deterministic random-numbers exist, few if any
2007 May 31
1
Restoring .Random.seed
Hi. Suppose I have a function which does some random number generation within. The random number generation inside the function changes the value of .Random.seed in the calling environment. If I want to restore the pre-function call .Random.seed, I can do: save.seed<-.Random.seed result<-myfunction() .Random.seed<-save.seed Is there a way to do the restoration inside the function?
2010 Apr 05
1
use of random and nested factors in lme
Dear all, I've read numerous posts about the random and nested factors in lme, comparison to proc Mixed in SAS, and so on, but I'm still a bit confused by the notations. More specifically, say we have a model with a fixed effect F, a random effect R and another one N which is nested in R. Say the model is described by Y~F Can anyone clarify the difference between : random = ~1|R:N random
2009 Dec 11
1
random effects in mixed model not that 'random'
...N(0, sigma) distribution. Integrating the biological knowledge as fixed effect however might be tremendously difficult, as species traits can sometimes not readily be quantified in a numeric way. I could defer issue to the species traits and say, once the species evolved their traits were drawn randomly from a population. This however causes problems with ideas of evolution and phylogenetic relationships among the species. Maybe my question can be rephrased the following way: Does it ever make sense to _interpret_ the coefficients of the random effects for each group and link it to properties...