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Has the Levene test of homogeneity of variance been implemented in any library in R? Thanks, Maurice Haynes National Institute of Child Health and Human Development Child and Family Research Section 6705 Rockledge Drive Bethesda, MD 20892 Voice: 301-496-8180 Fax: 301-496-2766 E-Mail: mh192j at nih.gov

Dear list members, Where can I find code for computing the p*p variance-covariance matrix given a vector of p variances (ordered varA, varB, ..., varp) and a vector of all possible correlations (ordered corAB, corAC, ..., corp-1,p)? I know that the covariance between 2 variables is equal to the product of their correlation and their standard deviations: corAB * varA^.5 * varB^.5 and so:

...: x86_64-unknown-linux-gnu (64-bit) Thanks, Adi Laurentiu TARCA, Ph.D. Assistant Professor (Research), Department of Computer Science & Center for Molecular Medicine and Genetics, Wayne State University, Director, Bioinformatics and Computational Biology Unit, Perinatology Research Branch (NICHD), 3990 John R., Office 4809, Detroit, Michigan 48201 Tel: 1-313-5775305 [[alternative HTML version deleted]]

...phics" "grDevices" "utils" "datasets" "methods" [7] "base" other attached packages: lme4 Matrix lattice "0.9975-13" "0.9975-11" "0.14-17" Thanks in advance for your help! -- Brian Riordan NICHD Postdoctoral Fellow Psychological and Brain Sciences Indiana University [[alternative HTML version deleted]]

Dear all, I often import data sets from other programs that contain user defined missing values. As an example consider a variable MXPLOCO with a user defined missing value of as -9. > summary(MXPLOCO) Min. 1st Qu. Median Mean 3rd Qu. Max. NA's -9.000 4.750 5.000 5.349 6.000 8.500 2.000 The following command successfully converts the value -9 to NA. However,

On Sun April 19, you posted the following on R-help: > After installing 2.9.0 I tried loading packages, but keep getting the following error. > > package 'robustbase' successfully unpacked and MD5 sums checked > Error in normalizePath(path) : > path[1]="C:\Program Files\R\R-2.9.0\library/robustbase": The system cannot find the file specified > I have had the

...rrently present at the MBL. We encourage graduate students and postdoctoral fellows as well as senior researchers to apply. PARTICIPANT FEE: $300 Accepted participants will be provided with shared dormitory accomodations at MBL and board. Support: National Institutes of Health-NIMH, NIA, NIAAA, NICHD/NCRR, NIDCD, NIDA, and NINDS. Organizers: David Kleinfeld (UCSD) and Partha P. Mitra (Bell Laboratories, Lucent Technologies). Website: www.vis.caltech.edu/~WAND/ Application: Send a copy of your c.v. together with a cover letter that contains a brief (ca. 200 word) paragraph on why you wish to...

Dear list members, How can I replace the nested for loops at then end of the script below with more efficient code? # Begin script__________________________________________________ # Dichotomous scores for 100 respondents on 3 items with # probabilities of a correct response = .6, .4, and .7, # respectively x1 <- rbinom(100,1,.6) x2 <- rbinom(100,1,.4) x3 <- rbinom(100,1,.7) #