search for: lcfltd

Displaying 20 results from an estimated 78 matches for "lcfltd".

2008 Jun 30
3
Is there a good package for multiple imputation of missing values in R?
...but I haven't been able to figure out how to get a new data frame with the imputed values replaced (I don't have Herrell's book). Any pointers would be appreciated. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2008 Apr 22
2
Multidimensional contingency tables
...ck black yes 6 8 black black no 97 The xtabs() function doesn't seem appropriate, as it has no means of using 'count'. This must be a common problem. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2011 Jun 05
3
How to convert a factor column into a numeric one?
..., as expected, although the result is numeric. The same happens if I use the order given by levels(df$Temp) instead of the sort order in the recode() 2nd argument. Any hints? ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2007 May 03
4
Survival statistics--displaying multiple plots
Hello all! I am once again analyzing patient survival data with chronic liver disease. The severity of the liver disease is given by a number which is continuously variable. I have referred to this number as "meld"--model for end stage liver disease--which is the result of a mathematical calculation on underlying laboratory values. So, for example, I can generate a Kaplan-Meier plot
2011 Feb 09
2
comparing proportions
Hi, I have a dataset that has 2 groups of samples. For each sample, then response measured is the number of success (no.success) obatined with the number of trials (no.trials). So a porportion of success (prpop.success) can be computed as no.success/no.trials. Now the objective is to test if there is a statistical significant difference in the proportion of success between the 2 groups of
2007 Sep 10
1
S-Plus "resample" package and associated functions
...packages in R that reproduce the package "resample" of S-Plus? The sample() function in R doesn't provide equivalent flexibility of bootstrap() and bootstrap2(). ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2008 Sep 25
1
R function which finds confidence interval for binomial variance
...acter of the sampling distribution for v (or v'). Does anyone know of an R package with R function that computes a reasonable confidence interval for v or v'? Thanks. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2010 Jun 21
2
Singularity in simple ANCOVA problem
...ndard error: 0.1787 on 6 degrees of freedom Multiple R-squared: 0.7464, Adjusted R-squared: 0.535 F-statistic: 3.532 on 5 and 6 DF, p-value: 0.07811 Why the NA's here? ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2009 Sep 03
1
Problem accessing functions in package 'roxygen'
...trim(" 1234") Error: could not find function "trim" I have a similar problem with trim.right(), trim.left() and other functions I've tried. Any ideas? ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2008 Apr 10
1
Problem installing and using package "tseries"
...uired file is at C:\Program Files\R\R-2.6.2\library\tseries\libs\tseries.dll. It is 36,864 bytes and looks superficially okay. Any ideas as to what's wrong here? Thanks. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2008 Aug 25
1
Specifying random effects distribution in glmer()
..." not found". My questions are: 1. Can this be done? 2. Am I using the right package and function? 3. What am I doing wrong? Any help would be appreciated. Thanks. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2008 Mar 08
1
How to do multi-factor stratified sampling in R
...or some pairs. This must be a common problem in data mining, but I don't seem to be able to locate the proper library or function for doing this in R. Thanks for any help. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2009 Jul 02
1
Getting identify() to work with lattice::cloud()
...tter what I use, when I click on a point I get warning: "no point within 0.25 inches". Does identify() work with cloud()? If so, what is the correct syntax. Thanks. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2007 May 27
1
How to reference or sort rownames in a data frame
...s can be done by writing new, brute force, functions scanning the subscripts, but there must be an (obvious?) direct way of doing this more elegantly. Thanks for any pointers. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2008 Jul 12
5
shapiro wilk normality test
Hi everybody, somehow i dont get the shapiro wilk test for normality. i just can?t find what the H0 is . i tried : shapiro.test(rnorm(5000)) Shapiro-Wilk normality test data: rnorm(5000) W = 0.9997, p-value = 0.6205 If normality is the H0, the test says it?s probably not normal, doesn ?t it ? 5000 is the biggest n allowed by the test... are there any other test ? ( i know qqnorm
2007 Apr 25
0
Use of Lexis function to convert survival data to counting format
...on't know how to find it. I would guess that it has something to do with 'start' and 'stop', of which arguments I am apparently clueless as to the meaning. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2007 Jul 23
0
Conditional logistic regression on n:m matched "cohort" data
...e in clogit() for this experiment. Is library('survival') clogit(result ~ lab + strata(specimen), method="exact", data=mydata) all that is required? Thanks. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2007 Jul 23
0
Conditional logistic regression on n:m matched "cohort" data [Corrected]
...it() for this experiment. Is library('survival') clogit(result ~ lab + method + strata(specimen), method="exact", data=mydata) all that is required? Thanks. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"
2007 Aug 24
1
chi-square statistics
I'm wondering if R has functions to return pvalues with given x-squares and df. I googled for it but couldn't seem to find one. Appreciate any helps here. An example: df=4, x<- c(33.69, 32.96, 30.90) which are the statistic for chi-square, I'd like to get the corresponding pvalues for each values in x. Thanks. -Karen [[alternative HTML version deleted]]
2007 Oct 18
0
Getting 'tilting' confidence intervals in R
...must be simple, but I'm not finding out the answer from the documentation. Also, use of any other packages to accomplish the tilting interval would also be useful. Thanks. ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral at lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causas scire"