search for: knoblick

Displaying 20 results from an estimated 28 matches for "knoblick".

2006 May 16
2
Interrater and intrarater variability (intraclass correlationcoefficients)
...erested in Hoyt's Anova which is a form of generalizability theory. This is usually estimated using by getting the variance components from ANOVA. > -----Original Message----- > From: r-help-bounces at stat.math.ethz.ch > [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Karl Knoblick > Sent: Tuesday, May 16, 2006 6:10 AM > To: r-help at stat.math.ethz.ch > Subject: [R] Interrater and intrarater variability > (intraclass correlationcoefficients) > > Hello! > > I want to calculate the intra- and interrater reliability of > my study. The design is v...
2004 Jul 26
3
Read SPSS data (*.sav) in R 1.8.0 (ok) and R1.9.1(error)
Hallo! I read SPSS data in the following way: library(Hmisc) library(foreign) dat<-spss.get("surv_abb.sav") In R1.9.1 I got the message: "Error in all(arg == choices) : Object "typeDate" not found" In R1.8.0 the same script works fine. Does anybody know a possibilty to read a SPSS file under R1.9.1? Thanks! Karl
2005 Mar 04
5
bayesmix - What is or where can I find JAGS executable?
Hallo! I want to use the package bayesmix. Trying the examples I had no success. The reason is, I think: > haveJAGS() [1] FALSE Have read of JAGS executable (I could not find JAGS.exe in my R directory). What is JAGS? Where can I find or download it? Karl
2006 May 16
5
Interrater and intrarater variability (intraclass correlation coefficients)
Hello! I want to calculate the intra- and interrater reliability of my study. The design is very simple, 5 raters rated a diagnostic score 3 times for 19 patients. Are there methods/funtions in R? I only found packages to calculate interrater variability and intraclass correlation coefficients for matrices of n*m (n subjects, m raters) - I have n subjects, m raters and r repetitions. Can
2004 Jan 17
3
Multiple groupedData plots in a postscript file using a loop
Hallo! I want to plot multiple grouped data in a postscript file using a loop. As I use a loop no plot (or just one empty plot) is generated. Here an example: library(nlme) data(Loblolly) # example data from nlme postscript("PSFile.ps") for (i in 1:1) # just as example { plot(Loblolly) } dev.off() Result: Just an empty PSFile.ps. (Withoput the loop it works. May anybody help? Karl
2008 Nov 10
6
Variable passed to function not used in function in select=... in subset
Hello! I have the problem that in my function the passed variable is not used, but the variable name of the dataframe itself?- difficult to explain, but an easy example: TestFunc<-function(df, group) { ??? print(names(subset(df, select=group))) } df1<-data.frame(group="G1", visit="V1", value=0.9) TestFunc(df1, c("group", "visit")) Result: [1]
2003 Dec 31
2
Plot grouped data: How to change x-axis? (nlme)
Hallo! GENERAL QUESTION: I'm trying to change the tick marks of the x-axis in a grouped data plot (nlme). CONCRETE EXAMPLE: In the example (see below) I want the x-axis to have tick marks at 0, 6, 12, 18, 24. How can I do this? WHAT I TRIED I tried "normal" methods like axis(...) but this does not work with this plot. And I also tried xlim=c(0,24) but the ticks are unchanged and
2007 Sep 26
1
Repeated tests against baseline
I came across a post by Karl Knoblick regarding the modeling of longitudinal data (see https://stat.ethz.ch/pipermail/r-help/2007-May/132137.html). I am often asked by physicians to perform what Karl refers to in his post as option 1: to perform paired t-tests against baseline at each follow up time point (30 days, 90 days, 6 months,...
2006 May 17
1
Response to query re: calculating intraclass correlations
...cribes six different ways to calculate ICCs from the same data set, all with different interpretations. All of the inputs for these calculations come from the repeated measures analysis which is described in P&B. Good luck! P. Message: 1 Date: Tue, 16 May 2006 10:09:54 +0000 (GMT) From: Karl Knoblick <karlknoblich at yahoo.de> Subject: [R] Interrater and intrarater variability (intraclass correlation coefficients) To: r-help at stat.math.ethz.ch Message-ID: <20060516100954.6267.qmail at web26504.mail.ukl.yahoo.com> Content-Type: text/plain; charset=us-ascii Hello! I want to calc...
2007 May 17
2
How to analyse simple study: Placebo-controlled (2 groups) repeated measurements (ANOVA, ANCOA???)
Hallo! I have two groups (placebo/verum), every subject is measured at 5 times, the first time t0 is the baseline measurement, t1 to t4 are the measurements after applying the medication (placebo or verum). The question is, if there is a significant difference in the two groups and how large the differnce is (95% confidence intervals). Let me give sample data # Data
2004 Jan 29
2
Calculating/understanding variance-covariance matrix of logistic regression (lrm $var)
Hallo! I want to understand / recalculate what is done to get the CI of the logistic regression evaluated with lrm. As far as I came back, my problem is the variance-covariance matrix fit$var of the fit (fit<-lrm(...), fit$var). Here what I found and where I stucked: ----------------- library(Design) # data D<-c(rep("a", 20), rep("b", 20)) V<-0.25*(1:40) V[1]<-25
2007 Jun 28
2
aov and lme differ with interaction in oats example of MASS?
Dear R-Community! The example "oats" in MASS (2nd edition, 10.3, p.309) is calculated for aov and lme without interaction term and the results are the same. But I have problems to reproduce the example aov with interaction in MASS (10.2, p.301) with lme. Here the script: library(MASS) library(nlme) options(contrasts = c("contr.treatment", "contr.poly")) # aov: Y ~
2004 Jun 29
1
nls fitting problems (singularity)
Hallo! I have a problem with fitting data with nls. The first example with y1 (data frame df1) shows an error, the second works fine. Is there a possibility to get a fit (e.g. JMP can fit also data I can not manage to fit with R). Sometimes I also got an error singularity with starting parameters. # x-values x<-c(-1,5,8,11,13,15,16,17,18,19,21,22) # y1-values (first data set)
2003 Nov 14
4
LOCF - Last Observation Carried Forward
Hi! Is there a possibilty in R to carry out LOCF (Last Observation Carried Forward) analysis or to create a new data frame (array, matrix) with LOCF? Or some helpful functions, packages? Karl --------------------------------- Gesendet von http://mail.yahoo.de Schneller als Mail - der neue Yahoo! Messenger. [[alternative HTML version deleted]]
2004 Jun 23
1
Fitting function with if-clause (nls; e.g. heaviside)
Hallo! I want to fit a function. The function is e.g.: y = c+m1*x if x<0, c+m2*x if x>=0 where m1, m2 and c is a parameter and x, y are variables of a data frame. I think using nls is appropriate. But I do not know, how to type this formula in nls. Can anybody help? (If there is a possibility to use a Heaviside-function this would be enough.) Karl
2004 Jul 27
0
Reading SPSS file
Hi Karl: a possible solution: require(foreign) mydata <- read.spss("somedata.sav", use.value.labels = TRUE, to.data.frame = TRUE) ----- for more information, try library(foreign) ?read.spss HTH, Arin Message: 21 Date: Mon, 26 Jul 2004 10:36:33 +0200 (CEST) From: Karl Knoblick <karlknoblich@yahoo.de> Subject: [R] Read SPSS data (*.sav) in R 1.8.0 (ok) and R1.9.1(error) To: r-help@stat.math.ethz.ch Message-ID: <20040726083633.90831.qmail@web52508.mail.yahoo.com> Content-Type: text/plain; charset=iso-8859-1 Hallo! <snipped....> Does anybody know a poss...
2004 Aug 30
1
Wrong result with cor(x, y, method="spearman", use="complete.obs") with NA's???
Hallo! Is there an error in cor to calculate Spearman correlation with cor if there are NA's? cor.test gives the correct result. At least there is a difference. Or am I doing something wrong??? Does anybody know something about this? a<-c(2,4,3,NA) b<-c(4,1,2,3) cor(a, b, method="spearman", use="complete.obs") # -0.9819805 cor.test(a, b,
2009 Jun 02
1
Sample size - proportion continuity correction
Hallo! Does anybody know how to calculate a sample size estimation for proportions with continuity correction? ? I only found EpiR which seems to calculate without continuity correction: library(epiR) epi.studysize(treat = .65, control = .50, n = NA, sigma = NA, power = 0.80, r = 1, conf.level = 0.95, sided.test = 2, method = "cohort") $n [1] 340 Thanks! Karl
2011 Aug 08
1
Sample size AUC for ROC curves
Hallo! Does anybody know a way to calculate the sample size for comparing AUC of ROC curves against 'by chance' with AUC=0.5 (and/or against anothe AUC)? Thanks! Karl
2010 Jul 14
1
Sample size ANCOVA
Hallo! Does anyone know a possibility to perform a sample size estimation for an ANCOVA? Would be great! Thanks Karl