similar to: FW: [R] same random numbers in different sessions

Displaying 20 results from an estimated 3000 matches similar to: "FW: [R] same random numbers in different sessions"

2008 Sep 11
2
Plot qnorm
Hi, I have this problem: X is hazardous variable N(mean 2, sd=3) >>question 1) Find the c value, so that P(X>c)=0.10. using R >>question 2) Graph the function N(2,3) and with this graph, explain what you do in question number 1. I just found question number one but not the second one. So, I'd like to make a plot form this distribution N (2,3) using the functions plot and
2008 Nov 24
14
how to test for the empty set
Dear R-help, I first thought that the empty set (for a vector) would be NULL. x <- c() x However, the documentation seems to make clear that there _many_ empty sets depending on the vector's mode, namely, numeric(0), character(0), logical(0), etc. This is borne out by y <- letters[1:3] z <- letters[4:6] intersect(y,z) which, of course, is non-NULL: is.null(character(0)) #
2010 Feb 02
3
Update problem? Rcmdr disappears, won't re-open
WinXP, R 2.10.1 I just updated R, and now have trouble. Perhaps it was the method I used to keep all the packages. I copied all the new packages from 2.10.1 back into the 2.10.0 folder, then copied them and all the others I've previously added from the 2.10.0 folder and pasted them back into 2.10.1's appropriate folder. Is this the source of my troubles? I am trying unsuccessfully to
2009 Mar 23
3
How to set up a function for "Central Limit Theorem"
Hello guys, I am stuck here: How do I make 1000 samples of n = 10 observations from an Exponential distribution and then compute the mean for all those 1000 samples? Basically I need to prove the Central Limit theorem, which states: http://www.nabble.com/file/p22664113/d175f06cbf200bd52a2c27a2e56dc594.png Where the Sn is sum of random variables, n we have from the question, mu is mean and
2009 May 30
3
setdiff bizarre (was: odd behavior out of setdiff)
Dear R-devel, Please see the recent thread on R-help, "Odd Behavior Out of setdiff(...) - addition of duplicate entries is not identified" posted by Jason Rupert. I gave an answer, then read David Winsemius' answer, and then did some follow-up investigation. I would like to change my answer. My current version of setdiff() is acting in a way that I do not understand, and a way
2009 May 30
3
setdiff bizarre (was: odd behavior out of setdiff)
Dear R-devel, Please see the recent thread on R-help, "Odd Behavior Out of setdiff(...) - addition of duplicate entries is not identified" posted by Jason Rupert. I gave an answer, then read David Winsemius' answer, and then did some follow-up investigation. I would like to change my answer. My current version of setdiff() is acting in a way that I do not understand, and a way
2009 May 29
2
Odd Behavior Out of setdiff(...) - addition of duplicate entries is not identified
I think I am using the improved version of setdiff(...) that handles data.frames, so I think some odd behavior was expected but this one is escaping me. It appears that the the addition of duplicate entries is not caught by the setdiff(...). Is this expected behavior? If so, is there another method or approach that should be used to identify duplicate row entries between two different data
2009 Dec 15
1
Starting with R and distributions graphics
HI, i'm really new of R and i need some help. I have to describe some distributions for some dices throw: - launching 3 dices i need the distribution of the sum of the two higher values - launching 4 dices i need the distribution of the occurrences of the same value possibly i need a way to compare the two distribution adding the fourth dice to the first without summing it (only for
2010 Mar 19
1
Gamma parametrization
Dear R users, ?rgamma gives me : rgamma(n, shape, rate = 1, scale = 1/rate) rate: an alternative way to specify the scale. The Gamma distribution with parameters ‘shape’ = a and ‘scale’ = s has density f(x)= 1/(s^a Gamma(a)) x^(a-1) e^-(x/s) Should I understand that scale=1/rate ? Is it written somewhere ? Then
2010 Sep 08
2
choose.dir() gone?
Hi, I fail to find "choose.dir()" in my current R install (see below)? Didn't that exist at some point? How to achieve "file.choose()" equivalent functionality for directories? Thanks for any hints, Joh > sessionInfo() R version 2.11.1 (2010-05-31) x86_64-pc-linux-gnu locale: [1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C [3]
2009 May 14
2
can you tell what .Random.seed *was*?
Dear R-help, Suppose I write a script that looks something like this: #### script.R set.seed(something) x <- rnorm(100) y <- runif(500) # bunch of other stuff save.image() ### end of script.R Now, I give you a copy of my script.R (with the set.seed statement removed, of course) together with the .RData file that was generated by the save.image() command. Question: 1) can you tell
2008 Aug 20
3
Writing Rcmdr Plugins
Dear all, I am trying to write a plugin for the RCommander and having troubles understanding how to actually do that. I have read Mr. Fox's tutorial about writing Rcmdr plugins and though.... it seems to me that some steps are missing. I would like to know, whether there are some Commands which generate a plugin package out of a given library. Or do we just have to attach the .First.lib
2007 Dec 10
1
setdiff for data frames
Hello, I have been interested in setdiff() for data frames that operates row-wise. I looked in the documentation, mailing lists, etc., and didn't find exactly the right thing. Given data frames A, B with the same columns, the goal is to extract the rows that are in A, but not in B. Of course, one can usually do setdiff(rownames(A), rownames(B)) but that is cheating. :-) I played around a
2010 Jul 27
2
Introductory statistics and introduction to R
Hi, I have a bright, diligent second-year graduate student who wants to learn statistics and R and will, in effect, be taking a tutorial from me on these subjects. (If you've seen some of my questions on this list, please don't laugh.) As an undergrad he majored in philosophy, so this will be his first foray into computer programming and statistics. I'm thinking of having him use
2009 Jan 04
1
Bivarite Weibull Distribution
HI Every one Could some one provide me definitions of following bivariate distributions gamma, exponencial, Weibull, half-normal , Rayleigh, Erlang,chi-square thanks A.S. Qureshi
2008 Jun 04
1
permsn incorrect when x==m (library: prob) (PR#11571)
Full_Name: Obnoxious Version: 2.7.0 OS: Windows Submission from: (NULL) (121.223.77.238) Objective: Generate all permutations of the elements of x taken m at a time. Library: prob Function: permsn Issue: Does not appear to be working correctly when x==m. Example: libary(prob) permsn(2,1) i.e., x > m #Gives the correct result of [,1] [,2] [1,] 1 2 #Yet permsn(2,2) i.e., x==m
2007 Sep 16
2
power calculation for repeated measures ANOVA?
Is there a way to calculate power for repeated measures ANOVA (2 groups x 7 observations)? I have searched all over, but all I can find is power.anova.test, but that would not give accurate results, right? Thanks, Matt Bridgman
2007 Dec 21
2
number of count of each unique row
Hi, I have a matrix of duplicate rows. How to output a list the unique rows with their count? I have used "unique" to have the unique rows, but can't produce the occurences of each unique row. Thanks Louis --------------------------------- [[alternative HTML version deleted]]
2009 Jul 30
1
Logistic regression and R
Hello everybody :-) I have some data that I want to model with a logistic regression, most of the independent variables are numeric and the only dependent is categorical, I was thinking that I could apply a logistic regression using glm but I wanted to deepen my knowledge of this so I tried to do some reading and found the "iris" dataset, now I would like to ask two things, first
2009 Dec 04
3
Combinations and joint probabilities
  Dear R helpers   Suppose I have two sets of ranges (interest rates) as   Range 1 : (7 – 7.50, 7.50 – 8.50, 8.50 – 10.00) with respective probabilities 0.42, 0.22 and 0.36.     Range II : (11-12, 12-14, 14-21) with respective probabilities 0.14, 0.56 and 0.30 respectively.     My problem is to form the combinations of these ranges in a decreasing order of joint probabilities. It is assumed that