similar to: R simulations

1) The Pareto P(alfa) distribution is defined by its density f(x|alfa) =alfa*X^(-alfa-1) over (1 to infinity). Show that it can be generated as the -1/alfa power of a uniforme variate. Plot the histogram and the density. 2) The Poisson distribution P(lambda) is connected to the exponential distribution through the Poisson process in that it can be simulated by generating exponential random

It is interesting to graph the distribution of the standardized average as n increases. Do this when the Xi are uniform on [0; 1]. Look at the histogram when n is 1, 5, 10 and 25. Do you see the normal curve taking shape? (A rule of thumb is that if the Xi are not too skewed, then n > 25 should make the average approximately normal. You might want > f=function(n,a=0,b=1) { mu=(b+a)/2

Dear forum users, It's 3:35am and I am swamped with statistics homework lol I'm terrible with R and this time I have no idea what the prof wants. Here is the question: Consider the (two-??sample) Wilcoxon rank statistic T = ?rank(Xi). For n1=106 and n2=192, determine by simulation the ?=.05 critical point for testing H0: ?=0, H1:?<0. We can do this as follows: For m=10000 (no wimpy

I am estimating a large model by groups. How do you save the results and?returns the associated quantiles? For this example I need a data frame n?? ?xi??????? mu????????beta 1?? 0.1033614? 2.5389580 0.9092611 2? ?0.3401922? 0.5192882 1.5290615 3?? 0.5130798? 0.5668308 1.2105666 I also want to apply gevrlevelPlot() for each "n" or group. ? #Example n <- c(1, 1, 1, 1, 1, 1, 2, 2, 2,

Hello, I have a bigger problem in calculating the Maximum Likelihood Estimator regarding the degree of freedom of a multivariate skew-t copula. First of all I would like to describe what this is all about, so that you can understand my problem: I have 2 time series with more than 3000 entries each. I would like to calculate a multivariate skew-t Copula that fits this time series. Notice:

1) dmatrix1<-function(n,p,rho,sigma,k){ muvec1=zeros(1,p) truep<-as.matrix(c(3,1.5,0,0,2,0,0,0)) A=eye(p) for(i in 1:p){ for(j in 1:p){ A[i,j]=rho^(abs(i-j)) X=mvrnorm(n,muvec1,A) y=X%*%truep+as.matrix(rnorm(n,0,sigma)) Y=X[1:k,] w=y[1:k] Z=X[(k+1):n,] z=y[(k+1):n]}} return(list(X,Y,w,Z,z)) } I made this code which performs

Hola, Esta pregunta la hice en stackoverflow <http://stackoverflow.com/questions/31137940/randomly-assign-teachers-to-classrooms-imposing-restrictions/31143808#31143808>pero nadie pudo contestarla. 1. Quiero generar N escuelas, con G grados y C divisiones. 2. Quiero asignar cada uno de T maestros a 2 divisiones en un grado y escuela Si tengo C=4 divisiones, puedo lograr lo que quiero con

Hola, 0. La falta de 'elegancia' hace que sea mas dificil hacer cambios al codigo. Por ejemplo cambiar n.classrooms <- 4 a n.classrooms <- 20 1. Cuando tengo solo 4 puedo hacer esto: schoolGrade$A <- Teachers$Teacher.ID[1:cuttoff1] schoolGrade$B <- Teachers$Teacher.ID[1:cuttoff1] schoolGrade$C <- Teachers$Teacher.ID[(cuttoff1+1):n.teachers] schoolGrade$D <-

Gracias Carlos, Tu codigo es un gran paso en el sentido correcto pero no produce exactamente lo que estoy buscando. Mi "solucion" en stackoverflow <http://stackoverflow.com/questions/31137940/randomly-assign-teachers-to-classrooms-imposing-restrictions/31143808#31143808> produce un data frame `schoolGrade` con 240 observaciones y 7 variables. Mi objetivo es poder generar un data

Perdon por no se lo suficientemente claro :( Tu codigo produce `validPairs` que tiene 7 variables y 360 observaciones. Donde > validPairs[1,] V1 V2 V3 V4 V5 V6 valid 60 e1 g1 c1 e1 g1 c2 Valid indica que un maestro tiene asignado c1 y c2 en la escuela e1 y el grado g1. Correcto? Si es asi, esto es casi lo que queira producir y creo que puedo llegar a donde quiero usando tu codigo de base.

I''m using Edge Rails and the new has_many :through in my code. What I''m trying to do is modify my create and update code to use the new relationships. I''m using a table called course_teachers for the joins. Here is what I have so far: def create @course = Course.new(params[:course]) @teacher = Teacher.find(params[:primary_teacher]) @course.teachers =

I wonder if you can have more than one has_many :through association between 2 models. For example... I have a model Teacher and a model Class Now, 1 Teacher works in many Classes, right?. So I need a join model like class Work < ActiveRecord::Base belongs_to :teacher belongs_to :class end But I also would like to know if a teacher CAN teach a class before I

I had this problem some last year and never got it figured out. Now it is bugging me. It seems that sometimes when a student writes his/her file to a directory, it will not keep the correct group. It puts his/her main group as the group owner and that fouls things up. Here is what I have. Unix Permissions /school 3777 admin.teacher /school/bhs 3777 admin.teacher /school/bhs/reese

I am trying to clean up unnecessary lines (even as I hack my way forward adding more garbage) I have two questions on lines I have trying to keep the database and session info reflecting changes: def associate_pupil_to_teacher @teacher = session[:teacher] @pupil = Pupil.find(params[:id]) @teacher.pupils << @pupil @teacher.save #Q1 session[:teacher] = @teacher #Q2 end #Q1 do i

Hi, I am trying to create a vector of length 10 (say), wherein each element will be average of random sample of size 100, from a distribution, say Normal. Can anyone please tell me without creating a "for" loop, how I can do that? Regards, -- View this message in context: http://www.nabble.com/Alternate-to-for-loop-tp22035954p22035954.html Sent from the R help mailing list archive at

Dears, I'm a college student and In doing my statistics homework. I use R with SEM package as my tool for sem analysis, but my teacher told me AMOS is more suitable for such analysis. Could someone help tell me whether it is true that some commercial software is better accepted in academic fields? Sorry if I should not post such topics here. -- Best Regards, Reeyarn T. Lee Accounting

On 06/04/15 12:37, buhorojo wrote: > On 05/04/15 19:41, Rowland Penny wrote: >> On 05/04/15 16:11, buhorojo wrote: >>> On 05/04/15 17:03, Reindl Harald wrote: >>>> >>>> >>>> Am 05.04.2015 um 16:55 schrieb buhorojo: >>>>> We don't want best anything >>>> >>>> sad enough >>>>

Hello, I am using the lmomco package (lmom.ub and pargev) to compute the GEV parameters (location, scale, and shape), which are used to estimate return values. I was wondering how/if I can calculate upper and lower confidence (CI_u, CI_l) intervals for each return frequency using the GEV parameters to fill-in the table below? Xi (location) = 35.396 Alpha (scale) = 1.726 Kappa (shape) =

On 05/04/15 16:11, buhorojo wrote: > On 05/04/15 17:03, Reindl Harald wrote: >> >> >> Am 05.04.2015 um 16:55 schrieb buhorojo: >>> We don't want best anything >> >> sad enough >> >>> We want what we have to work >> >> so do what you want - who cares >> >>> Linux: we configure it as we wish >> >> why

Hello, i have a strange problem here. I have made a teacher controller using scaffold. All actions work fine but the delete does not. When i click the delete link, it redirects me to the edit of this teacher. I have restarted the server and i have tried in firefox (i use chrome) but problem still remains. Here is the code from my view. <%= link_to(image_tag("/images/