Displaying 20 results from an estimated 600 matches similar to: "Fit t distribution"
2004 Feb 18
2
using names() as a variable in a formula
Greetings List,
I'm having some trouble with the use of the names function in a formula. Below is an example of something that works (i.e first line), and the second line is the same formula which doesn't. I want to be able to reference the column of the dataC table so I can run the variogram iteratively with a loop.
> v<-variogram(A1~1,loc=~x+y, dataC)
>
2009 Jun 22
3
Calculating "row standard deviations"
Hi R-helpers,
I have been struggling with calculating row and column statistics,
e.g. standard deviation.
I know that
> datac$Mean<-rowMeans(datac,na.rm=TRUE)
will give me row means.
I have tried to replicate those row means with the apply function:
> datac$Mean2<-apply(datac,2,mean)
so that I can replace the function argument with "sd" (instead of
mean) to get standard
2008 Dec 02
1
Left-truncated regression
Hi.
I am looking for a function for left-truncated data.
I have one data set with 2 variables (Hours~Yrs_Ed).
I already left-censored the data at 200 and left-truncated it at the same
spot, so that I am able to make 2 estimations (one for censoring and one for
truncation).
I know how to make the linear regression for the left-censored variable
(hours) and how to plot the regression line into the
2008 Apr 25
3
Use of survreg.distributions
Dear R-user:
I am using survreg(Surv()) for fitting a Tobit model of left-censored longitudinal data. For logarithmic transformation of y data, I am trying use survreg.distributions in the following way:
tfit=survreg(Surv(y, y>=-5, type="left")~x + cluster(id), dist="gaussian", data=y.data, scale=0, weights=w)
my.gaussian<-survreg.distributions$gaussian
2009 Jan 04
1
POSIXct and chron issues with tz
Dear All-
I am trying to merge two data files - they have different date formats
and different times zones. I need to match up the date/time of the
datasets and then invoke a conditional statement, such as: if dataC$mph
is >= 12 then keep dataM$co23 for the corresponding time/date stamp.
snippets of data files:
*dataC.txt*
LST in mph Deg DegF DegF2 % volts Deg
2010 Dec 07
2
robustbase problem [bug?] in adjbox function.
hello list,
i'm a bit puzzled by the error message i get when i copy past this in R:
2008 Mar 03
1
Problem plotting curve on survival curve
Calum had a long question about drawing survival curves after fitting a Weibull
model, using pweibull, which I have not reproduced.
It is easier to get survival curves using the predict function. Here is a
simple example:
> library(survival)
> tfit <- survreg(Surv(time, status) ~ factor(ph.ecog), data=lung)
> table(lung$ph.ecog)
0 1 2 3 <NA>
63 113 50 1
2012 Oct 19
1
Looping survdiff
The number of recent questions from umn.edu makes me wonder if there's homework involved....
Simpler for your example is to use get and subset.
dat <- structure(..... as found below
var.to.test <- names(dat)[4:6] #variables of interest
nvar <- length(var.to.test)
chisq <- double(nvar)
for (i in 1:nvar) {
tfit <- survdiff(Surv(time, completion==2) ~
2006 Jan 19
2
Tobit estimation?
Folks,
Based on
http://www.biostat.wustl.edu/archives/html/s-news/1999-06/msg00125.html
I thought I should experiment with using survreg() to estimate tobit
models.
I start by simulating a data frame with 100 observations from a tobit model
> x1 <- runif(100)
> x2 <- runif(100)*3
> ystar <- 2 + 3*x1 - 4*x2 + rnorm(100)*2
> y <- ystar
> censored <- ystar <= 0
2007 Jul 05
3
Loop and function
Hi All, I am trying to make a loop for a function and I am using the
following codes. "p" and "var" are some matrix obtained before. I would like
to apply the function "gpdlow" for i in 1:12 and get the "returnlow" for i
in 1:12. But when I ask for "returnlow" there are warnings and it turns out
some strange result.
for (i in 1:12){
gpdlow
2007 Jun 19
2
Histogram
Hello, I am using the following codes to plot a histogram and density line
for x. For the density line, I just want it to show the two tails, eg, for x
larger than 0.05 ans smaller than -0.05
hist (x, seq(-0.1,0.1,0.01),freq = FALSE)
lines (density(x,bw="SJ"), x> 0.05 & x< (-0.05), col = "red")
But is does not work, can anyone give me some advice?
--
View this
2007 Dec 03
2
Linear Regression, Data is a list
Hello,
I would like to perform a linear regression and the data is a list.e.g
lm(list$abc~., data=list) or lm(abc~., data=list), which would give the same
result.
The problem is I would like to call the response variable in a more general
form. What I try to achieve is sth like lm(list$(paste("a","b","c"))~.,
data=list), but it does not work.
Could anyone give me
2007 Oct 02
5
Linear Regression
Hello,
I would like to fit a linear regression and when I use summary(), I got the
following result:
Call:
lm(formula = weight ~ group - 1)
Residuals:
Min 1Q Median 3Q Max
-1.0710 -0.4938 0.0685 0.2462 1.3690
Coefficients:
Estimate Std. Error t value Pr(>|t|)
groupCtl 5.0320 0.2202 22.85 9.55e-15 ***
groupTrt 4.6610 0.2202 21.16 3.62e-14
2009 Feb 09
2
CMD check puzzle
I am getting an error that I don't understand from R CMD check on my current
instance of the survival code. R2.7.1 on Linux. Here is the last of the
log
* checking line endings in Makefiles ... OK
* checking for portable use of $BLAS_LIBS ... OK
* creating survival-Ex.R ... OK
* checking examples ... OK
* checking tests ...
make[1]: Entering directory
2007 Jun 19
2
Function -return value
Hi, I am trying to write a function with the following codes and I would like
it to return the values for "alpha
beta para parab " seperately. Then I would like to use this funstion for
"variable" with factor "a" and "b". But the result turns out to be a matrix
with element like "Numeric,2" ... I guess they are just the values for
2011 Oct 23
0
code review: is it too much to ask?
Hello all,
I really appreciate how helpful the people in this list are. Would it be too much to ask to send a small script to have it peer-reviewed? to make sure I am not making blatant mistakes? The script takes an experiment.dat as input and generates system Throughput using ggplot2. It works now ... [sigh] but I have this nasty feeling that I might be doing something wrong :). Changing
2007 Jul 10
3
ECDF, distribution of Pareto, distribution of Normal
Hello all,
I would like to plot the emperical CDF, normal CDF and pareto CDF in the
same graph and I amusing the following codes. "z" is a vector and I just
need the part when z between 1.6 and 3.
plot(ecdf(z), do.points=FALSE, verticals=TRUE,
xlim=c(1.6,3),ylim=c(1-sum(z>1.6)/length(z), 1))
x <- seq(1.6, 3, 0.1)
lines(x,pgpd(x, 1.544,0.4373,-0.2398), col="red")
y
2007 Jul 03
4
sequences
Hi, I would like to generate a series in the following form (0.8^1, 0.8^2,
..., 0.8^600)
Could anyone tell me how can I achieve that? I am really new to R.
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2007 Jun 29
2
cbind
Hi, I have a series of return data, a and b are factors. I would like to
build a matrix which contains each vector of "returns". I am thinking about
something as following, but I guess there should be a sensible way of doing
this.
returns <- split(return, list(regimef, assetf))
cbind(returns[[1]], returns[[2]],...,returns[[n]])
Could anyone give me some advice? Many thanks.
--
2007 Sep 17
2
vector name
I have got a list named "filtered", I would like to construct alist named
"fdata" as following:
fdata <- cbind(matrix(unlist(filtered),ncol=28), myregime)
If I try names(filtered), it gives all the correct name for each vector, but
if I try names(fdata), it appears "filtered[[1]]" "filtered[[2]]" ...,
How can I keep the name in "fdata"?