similar to: A statistical problem.Anybody can help me?

>From basic statistics principle,we know,given several i.i.d Gaussian RVs with zero or nonzero mean,the sum of square of them is a central or noncentral Chi-distributed RV.However if these Gaussian RVs have different variances,what does the sum of square of them obey? Thanks in advance.

I need to write a method for calculating the fee for medical procedures with respect to area. I have all the tables and data but its hard to give that here. Can someone take a look at this ''stub'' method and help me out? def calculate_fee # strip out the first 3 numbers of the user entered zip code # use those 3 numbers to identify row in [zipcodes table] (between upper and

Hello. It seems very very strange to me that nobody talks about connecting ISDN lines to asterisk using a device with RCAPI Support. There are some devices (most of them isdn routers, like the famous Cisco 800 family) that support this protocol. It basically is an ISDN to IP gateway. There used to be software that used this technology to send and receive faxes, act as voicemail and even ISDN

R users, I am having a problem with the modulus operator for large numbers as follows, a <- 2 n <- 561 ## n is the first Carmichael number, so by Fermat's Little Theorem the below should equal zero. (a^(n-1) - 1) %% n [1] 2.193172e+152 ## Seems that R and Fermat disagree ## Also, 1000000000000000000 %% 11 [1] -32 This seems like a bug. Should I be avoiding integer math for large

Dear All I am totally new to R and I would like to know whether R is able and appropriate to illustrate to my students the Central Limit Theorem, using for instance 100 independent variables with uniform distribution and showing that their sum is a variable with an approximated normal distribution. Thanks in advance, Paul

Hi all, I was wondering how to generate samples for two RVs X1 and X2. X1 ~ Bernoulli (p1) X2 ~ Bernoulli (p2) Also, X1 and X2 are correlated with correlation \rho. Regards, Vineet [[alternative HTML version deleted]]

Dear R people, This is a possibly silly question, but the rgamma function takes the shape and scale arguments and simulates gamma rvs corresponding to those values, right? But the shape and scale parameters have to be positive, right? However, rgamma quite happily returns to me values for negative values of shape and scale, and in some cases returns negative values eg. > rgamma(1, 1, -1) [1]

I have seen people say both that rsync can efficiently copy truecrypt volumes. I got it working once with deltacopy but as I'm trying to get it to work from the command line, I cannot. It just transfers the whole file. I am using -rvs -inplace switches. Does anybody have any suggestions? _____________________________ Stephen Zemlicka Integrated Computer Technologies PH.

Hi, How can I use "vhd-util" or "vhd-update"? Have someone a manual for this? A tutorial? Any help? I found this link (http://forums.citrix.com/message.jspa?messageID=1373599), but this link have a poor information. No examples. Anyone have an examples? Thanks. -- Roberto Scudeller Especialista Linux/Unix beto.rvs@gmail.com beto_rvs@yahoo.com.br

Hi Folks, Given k RVs with MVN distribution N(mu,S) (S a kxk covariance matrix), let (w.l.o.g.) X1 denote the first r of them, and X2 the last (k-r). Likewise, let mu1 and mu2 denote their respective expectations. Then, of course, the expectation of X2 given X1=x1 is mu2 + S21*inv(S22)*(x1 - mu1) and the covariance matrix of X2 given X1=x2 is S22 - S21*inv(X11)*S12 where Sij is the

Hi all, I try to use kernel 2.6.36.1 in HVM but building the drivers xen-blkfront, xenfs, platform-pci. I used Xen 4.0.2-rc1-pre and a DomU is a ubuntu 10.04 and I try with ubuntu 10.10. In boot I receive error "Cannot find a root partition /dev/xvda2" and a prompt (initramfs) appear. In dmesg (initramfs) appear: blkfront: xvda: barriers enabled (tag) xvda: xvda1 vbd vbd-51712: 16

Hi all, I try to use kernel 2.6.36.1 in HVM but building the drivers xen-blkfront, xenfs, platform-pci. I used Xen 4.0.2-rc1-pre and a DomU is a ubuntu 10.04 and I try with ubuntu 10.10. In boot I receive error "Cannot find a root partition /dev/xvda2" and a prompt (initramfs) appear. In dmesg (initramfs) appear: blkfront: xvda: barriers enabled (tag) xvda: xvda1 vbd vbd-51712: 16

How does one define PDFs as yet undefined in R, such as the ex- gaussian, the sum of two RVs, one exponential, one Gaussian? The PDF would then be the convolution of an exponential PDF, dexp(), and a normal, dnorm(). Kindly cc me in your reply to r-help. Thanks, _____________________________ Professor Michael Kubovy University of Virginia Department of Psychology USPS: P.O.Box 400400

On 25 September 2017 at 02:32, Mark D. Baushke <mdb at juniper.net> wrote: > [+CC Loganaden Velvindron <logan at hackers.mu>] primary author of > the RFC 4419 refresh draft. https://datatracker.ietf.org/doc/draft-lvelvindron-curdle-dh-group-exchange/ ? Tangent: has any consideration been given to increasing the maximum allowed beyond 8192 bits (which is below the current NIST

This is a relatively recent article that is somewhat accessible. Jensen, D. R., and Solomon, Herbert (1994), "Approximations to joint distributions of definite quadratic forms", Journal of the American Statistical Association, 89 , 480-486 It has references to previous work. I also have an old paper that is so old I can't tell what journal it came out of:( Grad, Arthur and Solomon,

Can someone explain why I am getting the following error: in the r code below? Error in solve.default(diag(2) + ((1/currvar) * (XX1 %*% t(XX1)))) : system is computationally singular: reciprocal condition number = 0 In addition: There were 50 or more warnings (use warnings() to see the first 50) The R code is part of a bigger program. ##sample from full conditional

Hi, All: Is there a simple way to detect complex conjugates in the roots returned by 'polyroot'? The obvious comparison of each root with the complex conjugate of the next sometimes produces roundoff error, and I don't know how to bound its magnitude: (tst <- polyroot(c(1, -.6, .4))) tst[-1]-Conj(tst[-2]) [1] 3.108624e-15+2.22045e-16i

Hi Folks, Can anyone give me the tip I've been groping for with the following question:? mu: kx2x2x2 array of reals corresponding to means of k RVs at the combinations of values (1,2)x(1,2)x(1,2) of dichotomous variables F1,F2,F3 mu prints out as k rows (one for each Xi) of 8 numbers M: N x (3+k) matrix of cases. The first 3 cols are values of

Dear list, I am using optim() function to MLE ~55 parameters, but it is very slow to converge (~ 25 min), whereas I can do the same in ~1 sec. using ADMB, and ~10 sec using MS EXCEL Solver. Are there any tricks to speed up? Are there better optimization functions? Thanks Toshihide "Hamachan" Hamazaki, $B_@:j=S=((JPhD Alaska Department of Fish and Game:

Hello, I have a question about how to plot a series of data. The folloqing is my data matrix of n > n 25p 5p 2.5p 0.5p 16B-E06.g 45379 4383 5123 45 16B-E06.g 45138 4028 6249 52 16B-E06.g 48457 4267 5470 54 16B-E06.g 47740 4676 6769 48 37B-B02.g 42860 6152 19276 72 35B-A02.g 48325 12863 38274 143 35B-A02.g 48410 12806 39013 175 35B-A02.g 48417 9057 40923