search for: erf

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 (2008) a <- 0.147 partc <- 1+a*x^2 partb <- 4/pi+a*x^2 parta...

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...

Do any of the R libraries have an implementation of the Inverse Error Function (Inverse ERF)? ref: http://mathworld.wolfram.com/InverseErf.html http://functions.wolfram.com/GammaBetaErf/InverseErf/ Thanks, Nathan [[alternative HTML version deleted]]

...n 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 = - sqrt(2)* erf-1 (2*P)), while R doesn't have a build in one. The InvErf function most people use is through qnorm( InvErf=function(x) qnorm((1+x)/2)/sqrt(2) ). When you type qnorm in the console, it doesn't show it as it is an internal function, I searched around can't found too much information, my...

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 and R version 2.5.0 (2007-04-23), produce a memory corruption Here is an example with core dump on ubuntu 7.04 AMD64, R version 2.5.0 (2007-04-23): >...

...e trials (about 2 sec). The brain activity was measured with magnetoencephalography (MEG), with a very high sample rate (1200 Hz). The activity from 275 MEG sensors was segmented precisely in relation to the onset of the cue. Each of these segments is known as an 'event-related field' or ERF and the segments for every cue left or cue right trial were averaged across trials (to improve signal-to-noise of the event-related activity). We have data that are averaged ERFs over several hundred trials. These averaged ERF for cue left or cue right was used to estimate the brain source activi...

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 . . . . . . . . . I want to select rows belonging to 7 random plots for 100 times. (There are...

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 Herausforderung f?r den Client den 2. F...

...ably,clang cribs looking at __builtin_iceil. Any idea how to resolve that as well? clang++ -O2 -march=bdver2 -mno-fma -save-temps -mfma4 -ffp-contract=fast -DSPEC_CPU_LP64 Compute.o ComputeList.o ComputeNonbondedUtil.o LJTable.o Molecule.o Patch.o PatchList.o ResultSet.o SimParameters.o erf.o spec_namd.o -o namd spec_namd.o: In function `main': spec_namd.ll:(.text+0x2a3): undefined reference to `__builtin_iceil' > Please open a bug report with a minimal test case > Will do. Thanks -Anitha > > > Ciao, Duncan. > > when com...

...s -fplugin=/home/anboyapa/install/bin/dragonegg.so -O2 -march=bdver2 -save-temps -fplugin=/home/anboyapa/install/bin/dragonegg.so -mno-fma -mfma4 -ffast-math -DSPEC_CPU_LP64 Compute.o ComputeList.o ComputeNonbondedUtil.o LJTable.o Molecule.o Patch.o PatchList.o ResultSet.o SimParameters.o erf.o spec_namd.o -o namd spec_namd.o: In function `main': spec_namd.C:(.text+0x2a3): undefined reference to `__builtin_iceil' collect2: error: ld returned 1 exit status specmake: *** [namd] Error 1 On 5 November 2012 14:32, Duncan Sands <baldrick at free.fr> wrot...

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

...ragonegg support for iceil would solve both problems. Ciao, Duncan. > clang++ -O2 -march=bdver2 -mno-fma -save-temps -mfma4 -ffp-contract=fast > -DSPEC_CPU_LP64 Compute.o ComputeList.o ComputeNonbondedUtil.o LJTable.o > Molecule.o Patch.o PatchList.o ResultSet.o SimParameters.o erf.o > spec_namd.o -o namd > spec_namd.o: In function `main': > spec_namd.ll:(.text+0x2a3): undefined reference to `__builtin_iceil' > > Please open a bug report with a minimal test case > > Will do. Thanks > -Anitha > > Ciao, Duncan. &...

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

...nboyapa/install/bin/dragonegg.so > -O2 -march=bdver2 -save-temps -fplugin=/home/anboyapa/install/bin/dragonegg.so > -mno-fma -mfma4 -ffast-math -DSPEC_CPU_LP64 Compute.o ComputeList.o > ComputeNonbondedUtil.o LJTable.o Molecule.o Patch.o PatchList.o ResultSet.o > SimParameters.o erf.o spec_namd.o -o namd > spec_namd.o: In function `main': > spec_namd.C:(.text+0x2a3): undefined reference to `__builtin_iceil' > collect2: error: ld returned 1 exit status > specmake: *** [namd] Error 1 > > > On 5 November 2012 14:32, Duncan Sands &l...

...cally for me (running R 2.4.1 under Windows XP 5.1 SP 2) for values of z near 37.4 or greater. Looking at the pnorm documentation I see that it is based on Cody (1993) and thence, going one step further back, on Cody (1969). Consulting Cody (1969) I see that the algorithm for pnorm(z) [or actually erf(z)] is actually based on rational function approximations for the reciprocal Mill's ratio itself, as I rather expected. I wonder if anyone has dug out a function for the reciprocal Mill's ratio out of the pnorm() code? Anticipating the obvious response I don't believe that this would b...

...with this error message: ------------ [...] Compiling regapi... rm -f regapi && ln -s ../../wine regapi Preparing to install default Wine registry entries... Installing default Wine registry entries... wineserver: request.c:235: write_request: Zusicherung ?thread->pass_fd == -1? nicht erf?llt. ------------ Any ideas? Platform ist Mandrake 7.2. My last try at wine was the codeveawers preview, but I have deinstalled this. TIA Ulrich.

...print("syntax: plot.spdf(min, max, skewlocation, skewscale, skewshape, skewmax, <skewtitle>)") flush.console() # sample input data could be the following: # -100, 1000, 976.02, 230, -34, 0.7543 # 0, 500, 270, 350, -13, 0.7707 # or any other data of similar form erf <- function(z) { ## Chebyshev fitting formula for erf(z) from ## Vetterling, W.T., , W.H. Press, S.A. Teukolsky, and B.P. Flannery. 1999. ## Numerical Recipes: Example Book [C], Second Edition. ## Cambridge University Press, NY. , Chapter 6-2. t <- 1...

Hello, Can someone point me to documentation on how to best backup a samba member server? I see the wiki currently does not contain one. Is it as simple as backup all shared folders with rysnc or similar that will preserve ACLS along with the smb.conf? I'm currently relying on a raid solution. Thanks. -- -James

Erf... Best backup are expensive :p Buy a backup robot, buy another one, put them in separated datacenters, which could on separated continent... I'm joking. But the question pushed me to. You can backup your data or backup your configuration. You can of course backup both. Then what configuratio...

Dear all, The package NORMT3 which computes the erf, erfc functions as well as the exact values of the convolution of a Gaussian with a Student's t 3 distribution has been enhanced with the addition of a function to compute Faddeeva's function. Thanks to Krishna Myneni for this addition. Guy Nason [[alternative HTML version deleted...