similar to: Inverse Error Function

how R implement qnorm() I wonder anyone knows the mathematical process that R calculated the quantile? The reason I asked is soly by curiosity. I know the probability of a normal distribution is calculated through integrate the Gaussian function, which can be implemented easily (see code), while the calculation of quantile (or Zα) in R is a bit confusing as it requires inverse error function (X

Hi all. I may be wrong, (and often am), but in trying to determine how to calculate the erf function, the documentation for 'pnorm' states: ## if you want the so-called 'error function' erf <- function(x) 2 * pnorm(x * sqrt(2)) - 1 ## and the so-called 'complementary error function' erfc <- function(x) 2 * pnorm(x * sqrt(2), lower=FALSE) Should, instead, it read:

Hi, I created a function for obtaining the normal cumulative distribution (I know all this already exists in R, I just wanted to verify my understanding of it). below is the code I came up with. cdf<-function(x) { erf<-function(x) { # approximation to the error function (erf) of the # normal cumulative distribution function # from Winitzki

>I'm rusty, but not *that* rusty here, I hope. > >If W (=Z*Z' in your case) is singular, it can not have >inverse, which by >definition also mean that nothing multiply by it will >produce the identity >matrix (for otherwise it would have an inverse and >thus nonsingular). > >The definition of a generalized inverse is something >like: If A is a >non-null

Dear All, My question is simple but I need someone to help me out. Suppose I have a positive definite matrix A. The funtion chol() gives matrix L, such that A = L'L. The inverse of A, say A.inv, is also positive definite and can be factorized as A.inv = M'M. Then A = inverse of (A.inv) = inverse of (M'M) = (inverse of M) %*% (inverse of M)' = ((inverse of

Hi, I have a dataset that looks like the one below. data plot plantno. species H 31 ABC D 2 DEF Y 54 GFE E 12 ERF Y 98 FVD H 4 JKU J 7 JFG A 55 EGD . . . . . . .

Hello all, In the course of trying to implement the CDF of an InverseGammaDistribution, I have run across the need for an igamma() function. Several others have needed this function but the answers I have found so far are not totally clear to me. I'm writing for three reasons: 1) to present a small error in the docs 2) to clarify the approach we are expected to take 3) to request,for the

Hi, all, Does anybody got the most general expression of a unitary matrix? I found one in the book, four entries of the matrix are: (cos\theta) exp(j\alpha); -(sin\theta)exp(j(\alpha-\Omega)); (sin\theta)exp(j(\beta+\Omega)); (cos\theta) exp(j\beta); where "j" is for complex. However, since for any two unitary matrices, their product should also be a unitary matrix. When I

Hello, I am currently using R to run an external program and then read the results the external program sends to the stdout which are tsv data. When R reads the results in it converts it to to a list of strings which I then have to maniuplate with a whole slew of commands (which, figuring out how to do was a reall challenge for a newbie like myself)--see below. Here's the code I'm

Hallo Liste, hat sich schon mal jemand mit 2 Faktor Auth f?r dovecot besch?ftigt? Es geht dabei nicht nur um die Absicherung einer Weboberfl?che sondern direkt die Absicherung der Standard pop/imap Verbindungen des Clients. Wir machen das auth bisher ?ber MySQL.? Rein technisch w?rde das gehen, da man die Password-Query beliebig anpassen und auch mit allow_nets arbeiten kann. Es w?re eher die

Hi Duncan I am facing a build error about __builtin_iceil when compiled with dragonegg using -ffast-math option. My dragonegg is built with gcc-4.7.0 (I am compiling namd spec benchmark here again). Any idea? g++ -march=bdver2 -save-temps -fplugin=/home/anboyapa/install/bin/dragonegg.so -O2 -march=bdver2 -save-temps -fplugin=/home/anboyapa/install/bin/dragonegg.so -mno-fma -mfma4 -ffast-math

On 6 November 2012 14:52, Duncan Sands <baldrick at free.fr> wrote: > Hi Anitha, > > > On 06/11/12 10:19, Anitha Boyapati wrote: > >> Hi Duncan >> I am facing a build error about __builtin_iceil >> > > it's surely just that dragonegg doesn't have any support for this builtin. > ok. Just verified that Target.cpp and x86_builtins do not have

Hi, I have some general questions about statistical analysis for a research dataset and a request for advice on using R and associated packages for a valid analysis of this data. I can only pose the problem as how to run multiple ANOVA tests on time series data, with reasonable controls of the family-wise error rate. If we run analysis at many small sections of a long time-series, the Type-I

Hi all, Looking to calculate the expected mean and variance of a ratio distribution where the source distributions are gaussian with known parameters and sample values are correlated. I see (from wikipedia: http://en.wikipedia.org/wiki/ Ratio_distribution#Gaussian_ratio_distribution) that this calculation is quite involved, so I'm hoping that someone has already coded a function to

hi all, Does anyone know which command to use for error function(erf)? Thanks

To R-helpers, R offers the polyroot function for solving mentioned equations iteratively. However, Dr Math and Mathworld (and other places) show in detail how to solve mentioned equations non-iteratively. Do implementations for R that are non-iterative and that solve mentioned equations exists? Regards, Mads Jeppe

I'm having trouble with the standard deviation distribution as shown on http://mathworld.wolfram.com/StandardDeviationDistribution.html . (Eric Weisstein references Kenney and Keeping 1951, which I can't check.) I believe the graphs they show, but when I code the function in R, according to the listed formula, I get very different graphs. Would someone please point out my error or tell

Full_Name: Benjamin Leblanc Version: 2.4.1 and 2.5.0 OS: Ubuntu Linux 7.04 AMD64 Submission from: (NULL) (195.83.84.213) Here is an example script that may crash under R with Linux AMD 64 bit platforms library('NORMT3') a <- 1:1000/1000 erf(a) I did several tests: - opensuse 10.2 x86_64 with R 2.4.1 and R 2.5.0, produce systematically a frozen R session - ubuntu 7.04 AMD64, R 2.4.1

I need to know how to do the following in puppet. Say I have three classes, (c1,c2,c3) that are not related. These classes could be considered "attributes" that may or may not apply to an individual host on my network. I need to know how to write a manifest, or series of manifests to allow me trigger a command (call it ''foo'') if all three classes are defined. I also

Hi Anitha, On 06/11/12 10:19, Anitha Boyapati wrote: > Hi Duncan > I am facing a build error about __builtin_iceil it's surely just that dragonegg doesn't have any support for this builtin. Please open a bug report with a minimal test case. Ciao, Duncan. when compiled > with dragonegg using -ffast-math option. My dragonegg is built with gcc-4.7.0 > (I am compiling namd