similar to: Integrate(dnorm) with different mean and standard deviation help

Displaying 20 results from an estimated 10000 matches similar to: "Integrate(dnorm) with different mean and standard deviation help"

2011 Sep 24
1
Help with Integration Output
Hi, I need to do a calculation in R which involves adding the estimate of a numerical integration with another number - however, if I add the number to the output of the intergrate function (which when run on its own provides me with a number with error), I get the message 'non-numeric argument to binary operator'. How would I be able to avoid this and use the estimate? eg: I have the
2006 Feb 10
3
Accuracy of dnorm (PR#8586)
Full_Name: Marco Vezzoli Version: 2.2.0 2.1.0 2.0.0 OS: Solaris, Windows, Linux Submission from: (NULL) (57.78.11.38) The dnorm functions yield a wrong value when the standard deviation is near to 1e-1 e.g. > dnorm(0,mean=0.04,sd=0.3) [1] 1.318039 this error is consistent in various version and os.
2006 Jan 20
2
big difference in estimate between dmvnorm and dnorm, how come?
Dear R community, I was trying to estimate density at point zero of a multivariate distribution (9 dimensions) and for this I was using a multinormal approximation and the function dmvnorm , gtools package. To have a sense of the error I tried to look the mismatch between a unidimensional version of my distribution and estimate density at point zero with function density, dmvnorm and dnorm. At
2005 Feb 10
2
Curious Behavior with Curve() and dnorm()
I am attempting to wrap the histogram function in my own custom function, so that I can quickly generate some standard plots. A part of what I want to do is to draw a normal curve over the histogram: > x <- rnorm(1000) > hist(x, freq=F) > curve(dnorm(x), lty=3, add=T) (for normal use, x would be a vector of empirical values, but the rnorm() function works for testing) That
2010 Dec 06
3
0.5 != integrate(dnorm,0,20000) = 0
Hello: The example "integrate(dnorm,0,20000)" says it "fails on many systems". I just got 0 from it, when I should have gotten either an error or something close to 0.5. I got this with R 2.12.0 under both Windows Vista_x64 and Linux (Fedora 13); see the results from Windows below. I thought you might want to know. Thanks for all your work in creating
2000 Nov 07
3
infinity in integrate function in R
sorry the integration was from -Inf to 1.96 The integrate function in R is not taking Inf (infinity). How do you use infinity in R. I was doing: integrate(dnorm,- Inf, 1.96) and I was getting Error: NA/NaN/Inf in foreign function call (arg 2). Obviously this should be equal to pnorm(1.96)= 0.9750021. How do you get around the infinity problem in R?
2003 Oct 31
4
dnorm() lead to a probability >1
Howdee, One of my student spotted something I can't explain: a probability >1 vs a normal probability density function. > dnorm(x=1, mean=1, sd=0.4) [1] 0.9973557 > dnorm(x=1, mean=1, sd=0.39) [1] 1.022929 > dnorm(x=1, mean=1, sd=0.3) [1] 1.329808 > dnorm(x=1, mean=1, sd=0.1) [1] 3.989423 > dnorm(x=1, mean=1, sd=0.01) [1] 39.89423 > dnorm(x=1, mean=1, sd=0.001) [1]
2008 Jul 08
1
odd dnorm behaviour (?)
#Quick one hopefully. Shouldn't dnorm be returning the pdf? Last time I checked, #a probability shouldn't be greater than 1 as produced by: curve(dnorm(x,0,.1),from=-1,to=t) #Shouldn't I be getting an axis more like that produced by: f=function(x,m,s){ y=rep(NA,length(x)) for(i in 1:length(x)){ y[i]=integrate( dnorm , upper=x[i]+sqrt(.Machine$double.eps) ,
2010 Sep 23
2
dnorm
Dear R-users Idea: Plot a dnorm line using specific mean/sd to complete a histogram (skewed). xs:range of y-values, ys: dnorm function Problem: I expected to multiply the ys function with the sample size (n=250-300). I was wondering about a factor between 12'000 and 30'000 to match the size of the dnorm line with the specific histogram. Thanks Sibylle hist(Biotree[Ld,]$Height2008,
2010 Nov 12
4
dnorm and qnorm
Hello all, I have a question about basic statistics. Given a PDF value of 0.328161, how can I find out the value of -0.625 in R? It is like reversing the dnorm function but I do not know how to do it in R. > pdf.xb <- dnorm(-0.625) > pdf.xb [1] 0.328161 > qnorm(pdf.xb) [1] -0.444997 > pnorm(pdf.xb) [1] 0.628605 Many thanks, Edwin -- View this message in context:
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
2007 Feb 26
3
returns from dnorm and dmvnorm
Hi All, Why would calls to dnorm and dmvnorm return values that are above 1? For example, > dnorm(0.00003,mean=0, sd=0.1) [1] 3.989423 This is happening on two different installations of R that I have. Thank you. Hailu [[alternative HTML version deleted]]
2011 Oct 23
1
how to plot a distribution of mean and standard deviation
Hi, I have the following data about courses (504) in a university, two attributes about the proportion of resources used (#resources_used / #resources_available), namely the average and the standard deviation. Thus I have: [1] n=504 rows [2] 1 id column and 2 attributes Here's a sample of the data: courseid,average,std 12741,1,0 17161,1,0 12514,1,0
2010 Jan 13
1
Formula for normal distribution with know mean and standard error and n terms
Hello, I am searching for a method to calculate a normal distribution. For example this equation is used to calculate the normal curve when the mean and standard deviation are know. p(x) = (1/?*sqrt(2?)) x exp (- (x-?)2/2?2) or (Embedded image moved to file: pic27350.jpg)Normal Probability Distribution Formula However, some of the literature I'm reading (I'm building an ecological
2006 Jul 14
3
Generating random normal distribution with mean 0 and standard deviation 1
Hello, This must be really simple, but I can't find it on R Site search. I need to generate a random normally distributed series with mean 0 and sd 1. In Matlab, this code is randn(n). The closest I found is runif(20,-1,1) but this forces a maximum and a minimum, and there's no way to specify a standard deviation of 1. >sd(runif(20,-1,1)) [1] 0.578164
2019 Dec 07
2
What should dnorm(0, 0, -Inf) return?
Hi, Apropos of a recent Inf question, I've previously wondered if dnorm "does the right thing" with dnorm(0, 0, -Inf) which gives zero. Should that be zero or NaN (or NA)? The help says "'sd < 0' is an error and returns 'NaN'" and since -Inf < 0 is TRUE, then... is this a bug? Thank you, Stephen Rochester, MN USA
2011 Feb 08
3
Perform one-way ANOVA using standard deviation and mean
Hi! I need to perform ANOVA on a couple of data sets. The only information I have are N, Mean and Standard deviation. I am very new to R, so can someone point me to the right direction on where to go? Thank you very much. Sincerely Niny Rao, PhD Philadelphia University
2010 Feb 10
1
Integral of function of dnorm
Dear all, How is it possible in R to calculate the following integral: Integral(-Inf, Inf)[log(dnorm(mean = 3, sd = 1))] how can I define that the density dnorm is taken on (-Inf, Inf) Thanks a lot! [[alternative HTML version deleted]]
2019 Dec 08
2
What should dnorm(0, 0, -Inf) return?
Yes, that looks like a bug and an easily fixable one too. However, I spy another issue: Why do we check the !R_FINITE(x) && mu == x before checking for sd < 0 ? The difference is whether we return ML_NAN; or ML_ERR_return_NAN; but surely negative sd should always be an error? I'd be inclined to do if (sigma < 0) ML_ERR_return_NAN; if(!R_FINITE(sigma)) return R_D__0;
2010 Aug 25
1
Estimate average standard deviation of mean of two dependent groups
Dear R-experts! I am currently running a meta-analysis with the help of the great metafor package. However I have some difficulties setting up my raw data to enter it to the meta-analysis models. I have a group of subjects that have been measured in two continuous variables (A & B). I have the information about the mean of the two variables, the group size (n) and the standard deviations of