similar to: Generate data - function

Displaying 20 results from an estimated 10000 matches similar to: "Generate data - function"

2009 Apr 08
3
MLE for bimodal distribution
Hello everyone, I'm trying to use mle from package stats4 to fit a bi/multi-modal distribution to some data, but I have some problems with it. Here's what I'm doing (for a bimodal distribution): # Build some fake binormally distributed data, the procedure fails also with real data, so the problem isn't here data = c(rnorm(1000, 3, 0.5), rnorm(500, 5, 0.3)) # Just to check
2009 Dec 15
1
Help in R
Hello, Can anyone give me some suggestion in term of calculating the sum below. Is there a function in R that can help doing it faster? x1, x2, ...xn where xi can be 0 or 1. I want to calculate the following: sum{ beta[a+sum(xi), b+n-sum(xi) ]* [ (1-x1)dnorm(0,1)+x1dnorm(2,1) ]* [ (1-x2)dnorm(0,1)+x2dnorm(2,1) ]* ...* [ (1-xn)dnorm(0,1)+xndnorm(2,1) ] } The sum in the beginning is over all
2006 Sep 27
3
t-stat Curve
Number of subjects = 25 Mean of Sample = 77 Standard Deviation (s) = 12 sem = 2.4 df = 24 The claim is that population mean is less than 80 * > 80 So our H0 (null hupotheis) is * > 80 > qt(.95,24) [1] 1.710882 > qt(0.05, 24) [1] -1.710882 tstat = -1.25 on t24 falls between 1.711 (.95,24) and *1.711 (.005,24) How Could I sketch t curve for the above data where my * would be at the
2004 Sep 16
3
Estimating parameters for a bimodal distribution
For several years, I have been using Splus to analyze an ongoing series of datasets that have a bimodal distribution. I have used the following functions, in particular the ms() function, to estimate the parameters: two means, two standard deviations, and one proportion. Here is the code I've been using in S: btmp.bi <- function(vec, p, m1, m2, sd1, sd2) {
2007 Feb 23
4
How to plot two graphs on one single plot?
Hi, I am trying to plot two distribution graph on one plot. But I dont know how. I set them to the same x, y limit, even same x, y labels. Code: x1=rnorm(25, mean=0, sd=1) y1=dnorm(x1, mean=0, sd=1) x2=rnorm(25, mean=0, sd=1) y2=dnorm(x2, mean=0, sd=1) plot(x1, y1, type='p', xlim=range(x1,x2), ylim=range(y1, y2), xlab='x', ylab='y') plot(x2, y2, type='p',
2003 Apr 10
1
how to estimate parameters of multimodal distribution
Dear all Please, is there any function or package for dealing with multimodal distributions? I try to fit multimodal distribution or more precisely to find out mixture of normal distributions which can lead to my actual data. I use optim to find (in that case) two parameters but what I want is to let the function find out arbitrary number of normal distributions underlaying my actual data
2001 May 10
3
lookup function for density(...) objects
Hi folks: Is there a lookup function that returns the variate given the cumulative probability for an object returned by the density(...) function? > mydata _ as.vector(mymatrix) > mydata.density _ density(mydata) > mydata.p80 _ lookup(mydata.density, p=0.8) # is there any function to accomplish this task? Thanks. Rajiv. -------- Rajiv Prasad, Postdoctoral Research Associate,
2010 Sep 05
1
Add y-title to a plot with two y axis
Hi all, We managed to plot two series on the same graph, with two y-axis, however, we haven't managed to add a title to the second y-axis x1=rnorm(25, mean=0, sd=1) y1=dnorm(x1, mean=0, sd=1) x2=rnorm(25, mean=0, sd=1) y2=dnorm(x2, mean=0, sd=1) plot(x1, y1, type='p', xlab='x', ylab='y') par(new=TRUE) plot(x1, y2, type='p', axes= FALSE,
2007 Oct 13
2
How to identify the two largest peaks in a trimodal distribution
Hello all I'm trying to do a simulation that involves identifying the minimum point between two peaks of a (usually) bimodal distribution. I can do this easily if there are only two peaks: CnBdens<-density(Ys/Xs) #probability density function for ratio of Ys to Xs for(p in 1:512) ifelse(CnBdens$y[p]>CnBdens$y[p-1],peak1<-p,break) #identifies first peak in probability
2000 Jan 12
1
Usage of p/d/qnorm
Hello, could You please help: I am looking for a way to formulate test accuracy measures such as test sensitivity, specificity, predictive values, and correct classification rate using p/d/qnorm. The tests' primary values follow a bimodal distribution, which is modelled by a mixture of two normal distributions: p * dnorm ((x - u1) / s1) / s1 + (1 - p) * dnorm ((x - u2) / s2) / s2)
2007 Mar 25
1
eliminating panel borders from lattice plots
I am trying to eliminate panel borders from my lattice plots. By default, they always print. For example: library(lattice) x <- seq(-3,3,length=1000) y1 <- dnorm(x) y2 <- dnorm(x, sd=.5) data <- data.frame(x=rep(x,2), y=c(y,y2), panel=rep(c(1,2), each=1000)) dplot <- xyplot(y~x | panel, data=data, strip=F, scales=list(draw=F))
2013 Mar 18
2
Fit a mixture of lognormal and normal distributions
Hello I am trying to find an automated way of fitting a mixture of normal and log-normal distributions to data which is clearly bimodal. Here's a simulated example: x.1<-rnorm(6000, 2.4, 0.6)x.2<-rlnorm(10000, 1.3,0.1)X<-c(x.1, x.2) hist(X,100,freq=FALSE, ylim=c(0,1.5))lines(density(x.1), lty=2, lwd=2)lines(density(x.2), lty=2, lwd=2)lines(density(X), lty=4) Currently i am using
2018 Feb 25
3
include
Thank you Jim, I read the data as you suggested but I could not find K1 in col1. rbind(preval,mydat) Col1 Col2 col3 1 <NA> <NA> <NA> 2 X1 <NA> <NA> 3 Y1 <NA> <NA> 4 K2 <NA> <NA> 5 W1 <NA> <NA> 6 Z1 K1 K2 7 Z2 <NA> <NA> 8 Z3 X1 <NA> 9 Z4 Y1 W1 On Sat, Feb 24, 2018 at 6:18 PM, Jim
2007 Mar 08
2
curve of density on histogram
Hi R users, I would like to know why these following curve densities don't appear correctly on the histograms. Thank you for your help library(lattice) library(grid) resp <- rnorm(2000) group <- sample(c("G1", "G2", "G3", "G4"), replace = TRUE, size = 1000) histogram(~ resp | group, col="steelblue", panel = function(x, ...){ std
2007 Jun 25
3
How to shadow 'power' area?
Dear all, Suppose I plot two normal distributions (A and B) side by side and add vertical line which hipotheticaly represent alpha value; e.g.: x <- seq(-3.5,5, length=1000) y <- dnorm(x) # Plot distribution A plot(y~x, type='l',axes=F,xlab="",ylab="",lwd=2) # Plot distribution B y2 <- dnorm(x-1.5) lines(y2~x,lwd=2) # Plot vertical line for alpha value
2018 Feb 25
2
include
HI Jim and all, I want to put one more condition. Include col2 and col3 if they are not in col1. Here is the data mydat <- read.table(textConnection("Col1 Col2 col3 K2 X1 NA Z1 K1 K2 Z2 NA NA Z3 X1 NA Z4 Y1 W1"),header = TRUE,stringsAsFactors=FALSE) The desired out put would be Col1 Col2 col3 1 X1 0 0 2 K1 0 0 3 Y1 0 0 4 W1 0 0 6 K2 X1
2010 Mar 20
2
EM algorithm in R
Please help me in writing the R code for this problem. I've been solving this for 4 days. It was hard for me to solve it. It's a simulation problem in R. The problem is My true model is a normal mixture which is given as 0.5 N(-0.8,1) + 0.5 N(0.8,1). This model has two components. I will get a random sample of size 100 from this model. I will do this 300 times. That means, I will have
2006 Mar 21
1
Simulate Mixture Model data
Dear R Users?? I woould like to generate mixture model data. I try two type method as followings two method, can anyone tell me which is right? or better? 1. generate two vectors data y1 and y2 from f1 and f2 seperately, and calculate y=alpha1*y1+alpha2*y2, 2. generate prob=unif(1), if prob <alpha1 y=y1, else y=y2. Can anyone give me some idea? Thanks so much! Goeland goeland at
2018 Feb 25
0
include
Hi Val, My fault - I assumed that the NA would be first in the result produced by "unique": mydat <- read.table(textConnection("Col1 Col2 col3 Z1 K1 K2 Z2 NA NA Z3 X1 NA Z4 Y1 W1"),header = TRUE,stringsAsFactors=FALSE) val23<-unique(unlist(mydat[,c("Col2","col3")])) napos<-which(is.na(val23)) preval<-data.frame(Col1=val23[-napos],
2018 Feb 25
2
include
Sorry , I hit the send key accidentally here is my complete message. Thank you Jim and all, I got it. I have one more question on the original question What does this "[-1] " do? preval<-data.frame(Col1=unique(unlist(mydat[,c("Col2","col3")]))[-1], Col2=NA,col3=NA) mydat <- read.table(textConnection("Col1 Col2 col3 Z1 K1 K2 Z2