Displaying 20 results from an estimated 3000 matches similar to: "truncated normal"
2007 Nov 24
2
how to compute highest density interval?
Suppose i want to compute a 95% highest density for a beta distribution
beta(a,b)
the two end points x1 and x2 shoudl satisfy the following two equations:
pbeta(x1,a,b)-pbeta(x2,a,b)=95%
dbeta(x1,a,b)=dbeta(x2,a,b)
Is there any fast way to compute x1 and x2 in R?
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2006 Aug 16
3
fitting truncated normal distribution
Hello,
I am a new user of R and found the function dtnorm() in the package msm.
My problem now is, that it is not possible for me to get the mean and sd out of a sample when I want a left-truncated normal distribution starting at "0".
fitdistr(x,dtnorm, start=list(mean=0, sd=1))
returns the error message
"Fehler in "[<-"(`*tmp*`, x >= lower & x <= upper,
2002 May 09
2
truncated normal
Does anyone know of an R-function that will generate an observation from a
truncated normal (left or right) with a mu and sigma2? Any correspondence
would be greatly appreciated.
Best regards, Scott Summerill
FAA ACB-330
SIGNAL Corp.
609-485-6377
scott.ctr.summerill at tc.faa.gov
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2009 Nov 15
4
pairs
Hi, All,
I have an n by m matrix with each entry between 1 and 15000. I want to know
the frequency of each pair in 1:15000 that occur together in rows. So for
example, if the matrix is
2 5 1 6
1 7 8 2
3 7 6 2
9 8 5 7
Pair (2,6) (un-ordered) occurs together in rows 1 and 3. I want to return
the value 2 for this pair as well as that for all pairs. Is there a fast way
to do this avoiding loops?
2008 Aug 23
2
how to call a C-library in R
Hi, everyone,
I need to use a C library. But since I have little experience in C, I want
to call this C library in R and program the rest in R. Does anyone know how
to do this?
Thanks,
Cindy
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2009 Aug 10
2
matrix power
Hi, All,
If I have a symmetric matrix, how can I get the negative square root of the
matrx, ie. X^(-1/2) ?
Thanks,
Cindy
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2009 Jul 27
2
local regression using loess
Hi, All,
I have a dataset with binary response ( 0 and 1) and some numerical
covariates. I know I can use logistic regression to fit the data. But I want
to consider more locally. So I am wondering how can I fit the data with
'loess' function in R? And what will be the response: 0/1 or the probability
in either group like in logistic regression?
Thank you,
Cindy
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2009 Jul 29
2
install package from CRAN
Hi,
I have a very basic question about install packages from CRAN on unix. I
only installed on Windows before. Should I use the command install.package?
The error message I got is
syntax error near unexpected token `"mvtnorm"'
Is it because I didn't set the path? Which path should I specify?
Thanks,
Cindy
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2009 Jul 26
1
normal mixture model
Hi, All,
I want to fit a normal mixture model. Which package in R is best for this? I
was using the package 'mixdist', but I need to group the data into groups
before fitting model, and different groupings seem to lead to different
results. What other package can I use which is stable? And are there
packages that can automatically determine the number of components?
Thank you,
Cindy
2008 Jul 24
1
R-package install
Hi, I have a R package, which is a .tar.tar file. And it is said to be
source code for all platforms. And the author said it should install on any
system (but he didn't know about Windows). I am wondering if I can use this
package in Windows R.
Thank you,
Cindy
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2011 Apr 09
1
integration
Hi, All,
I have a density function with 3 variables which is defined on some
irregular domain, and I want to get the marginal distribution of each
variable. Is there any function doing this?
A simple example is p(x,y,z)=x*y*z*I(xy>z). So each marginal distribution is
a function of the other two variables. My density form is very complicated,
so I cannot do it by hand. I was just wondering if
2009 Feb 09
1
question about mean
Hello, everyone,
I have a matrix like following:
school value
A .1
A .2
A .15
A .2
B .3
B .5
C .3
C .3
C .4
C .5
C .6
C .9
C 1
I want to get the mean 'value' for each 'school', but each school has
different length. Is there any way to do this fast? Because my
2009 Sep 20
3
plotting least-squares regression against x-axis
Hi,
I want to plot the residuals of a least-squares regression.
plot(lm(y~x), which=1)
does this, but it plots the y-axis of my data on the x-axis of the
residuals plot. That is, it plots the residual for each y-value in the
data. Can I instead use the x-axis of my data as the x-axis of the
residuals plot, showing the residual for a given x?
Thanks!
Jason Priem
University of North
2011 Oct 06
2
KS test and theoretical distribution
> x <- runif(100)
> y <- runif(100)
> ks.test(x,y)
Two-sample Kolmogorov-Smirnov test
data: x and y
D = 0.11, p-value = 0.5806
alternative hypothesis: two-sided
ok I expected that, but:
> ks.test(runif(100), "runif")
One-sample Kolmogorov-Smirnov test
data: runif(100)
D = 0.9106, p-value < 2.2e-16
alternative hypothesis: two-sided
How
2004 Feb 18
2
Area between CDFs
Dear List:
I am trying to find the area between two ECDFs. I am examining the gap in performance between two groups, males and females on a student achievement test in math, which is a continuous metric.
I start by creating a subset of the dataframe
male<-subset(datafile, female="Male")
female<-subset(datafile, female="Female")
I then plot the two CDFs via
2006 Jun 10
3
sparse matrix, rnorm, malloc
Hi,
I'm Sorry for any cross-posting. I've reviewed the archives and could
not find an exact answer to my question below.
I'm trying to generate very large sparse matrices (< 1% non-zero
entries per row). I have a sparse matrix function below which works
well until the row/col count exceeds 10,000. This is being run on a
machine with 32G memory:
sparse_matrix <-
2006 Aug 18
0
Fitting Truncated Lognormal to a truncated data set (was: fitting truncated normal distribution)
Dear List,
I am trying to fit Truncated Lognormal to a data set that is
'truncated' from above a certain value, say, 0.01. Below is what I
was able to come up with. I would appreciate it if you could review
and make any necessary changes.
# This is modified off the code for 'dtnorm' of library(msm).
dtlnorm <- function (n, mean = 0, sd = 1, lower = -Inf, upper = Inf)
{
2009 Mar 10
6
Pseudo-random numbers between two numbers
I would like to generate pseudo-random numbers between two numbers using
R, up to a given distribution,
for instance, rnorm.
That is something like rnorm(HowMany,Min,Max,mean,sd) over
rnorm(HowMany,mean,sd).
I am wondering if
dnorm(runif(HowMany, Min, Max), mean, sd)
is good. Any idea? Thanks.
-james
2011 Jun 02
4
[Plea to the R Gods] Theoretical and Empirical CDFs
http://r.789695.n4.nabble.com/file/n3567636/ecdfs.jpg ecdfs.jpg
http://r.789695.n4.nabble.com/file/n3567636/ecdf_curve.gif ecdf_curve.gif
Hello,
I have generated a plot of two empirical CDFs (attachment 1). As a result,
they are stepwise when plotted. The following code was used:
> plot(ecdf(mut), do.points=FALSE, verticals=TRUE, xlim=range(mut, non),
> col="red")
>
2011 Aug 22
2
CDFs
Hello all,
I have two columns of numbers. I would like to do the following:
(1) Plot both cdfs, F1 and F2 on the same graph.
(2) Find smoothed approximations of F1 and F2 lets call them F1hat and F2hat
(3) Find values for F1hat when we substitue a value of x in it.
(4) Find the corresponding densities of the cdfs.
Any ideas?
--
Thanks,
Jim.
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