search for: geriatric

...fuction to the columns of a data frame? (I can't covert data5NonEventsEpochs to a matrix as it contains character data). Thank you, John John David Sorkin M.D., Ph.D. Professor of Medicine Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology and Geriatric Medicine Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 (Phone) 410-605-7119 (Fax) 410-605-7913 (Please call phone number above prior to faxing) Confidentiality Statement: This email message, including any attachments, is for the sole use of the inten...

Hello, I want to find the roots of an equation in two variables. I am aware of the uniroot function, which can do this for a function with a single variable (as I understand it...) but cannot find a function that does this for an equation with more than one variable. I am looking for something implementing similar to a Newton-Raphson algorithm. Thanks. -- Bill Shipley North American Editor for

...f simulation results? I know that `try' can be used to capture errors, but I would like to capture and detect warnings. Any pointers would be appreciated. Thanks, Ravi. ____________________________________________________________________ Ravi Varadhan, Ph.D. Assistant Professor, Division of Geriatric Medicine and Gerontology School of Medicine Johns Hopkins University Ph. (410) 502-2619 email: rvaradhan at jhmi.edu

...declaration either, but then I haven't quite figured out how best to do variable substitutions in R. Thanks for any help. Cheers Jon Soli Deo Gloria Jon Erik Ween, MD, MS Scientist, Kunin-Lunenfeld Applied Research Unit Director, Stroke Clinic, Brain Health Clinic Baycrest Centre for Geriatric Care Assistant Professor, Dept. of Medicine, Div. of Neurology University of Toronto Faculty of Medicine Posluns Building, 6th Floor, Room 644 Baycrest Centre for Geriatric Care 3560 Bathurst Street Toronto, Ontario M6A 2E1 Canada Phone: 416-785-2500 x3636 Fax: 416-785-2484 Email: jween@klar...

...from the conditional [U | T=t] which is also a lognormal (parametrized by r). Does this sound right? Are there better/simpler ways to do this? Thanks very much for any hints. Best, Ravi. ------------------------------------------------------- Ravi Varadhan, Ph.D. Assistant Professor, Division of Geriatric Medicine and Gerontology School of Medicine Johns Hopkins University Ph. (410) 502-2619 email: rvaradhan@jhmi.edu<mailto:rvaradhan@jhmi.edu> [[alternative HTML version deleted]]

...-1.2,1), fr)) Now, `fvals' contains character elements, but I would like to obtain the actual numerical values. How can I do this? Thanks very much for any suggestions. Best, Ravi. ------------------------------------------------------- Ravi Varadhan, Ph.D. Assistant Professor, Division of Geriatric Medicine and Gerontology School of Medicine Johns Hopkins University Ph. (410) 502-2619 email: rvaradhan@jhmi.edu<mailto:rvaradhan@jhmi.edu> [[alternative HTML version deleted]]

...=0.8, T=10, delay=5) Is there a way to incorporate delay in odesolve? Any hints would be much appreciated. Ravi. ---------------------------------------------------------------------------- ------- Ravi Varadhan, Ph.D. Assistant Professor, The Center on Aging and Health Division of Geriatric Medicine and Gerontology Johns Hopkins University Ph: (410) 502-2619 Fax: (410) 614-9625 Email: rvaradhan@jhmi.edu Webpage: http://www.jhsph.edu/agingandhealth/People/Faculty/Varadhan.html ---------------------------------------------------------------------------- -------- [[alter...

...s "2020-09-17_00:00:00" How can I convert the elements into a valid R date-time constant? Thank you, John John David Sorkin M.D., Ph.D. Professor of Medicine, University of Maryland School of Medicine; Associate Director for Biostatistics and Informatics, Baltimore VA Medical Center Geriatrics Research, Education, and Clinical Center;? PI?Biostatistics and Informatics Core, University of Maryland School of Medicine Claude D. Pepper Older Americans Independence Center; Senior Statistician University of Maryland Center for Vascular Research; Division of Gerontology and Paliative Care,...

...d in a simulation of a repeated measures ANOVA given a known (1) within-person correlation with known (2) mean and SD of data obtained at each of three times of observation? Thanks, John John Sorkin Chief Biostatistics and Informatics Univ. of Maryland School of Medicine Division of Gerontology and Geriatric Medicine JSorkin at grecc.umaryland.edu Confidentiality Statement: This email message, including any attachments, is for th...{{dropped:6}}

...convergence properties of a certain class of numerical schemes for iteratively solving linear (and nonlinear) system of equations. -------------------------------------------------------------------------- Ravi Varadhan, Ph.D. Assistant Professor, The Center on Aging and Health Division of Geriatric Medicine and Gerontology Johns Hopkins Univerisity Ph: (410) 502-2619 Fax: (410) 614-9625 Email: <mailto:rvaradhan@jhmi.edu> rvaradhan@jhmi.edu -------------------------------------------------------------------------- [[alternative HTML version deleted]]

...RVNTN, TimePtID) : ?+? not meaningful for factors 2: In Ops.factor(INTRVNTN, TimePtID) : ?*? not meaningful for factors Thank you, John John David Sorkin M.D., Ph.D. Professor of Medicine Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology and Geriatric Medicine Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 (Phone) 410-605-7119 (Fax) 410-605-7913 (Please call phone number above prior to faxing) [[alternative HTML version deleted]]

David, predict.glm and se.fit were exactly what I was looking for. Many thanks! John John David Sorkin M.D., Ph.D. Professor of Medicine Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology and Geriatric Medicine Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 (Phone) 410-605-7119 (Fax) 410-605-7913 (Please call phone number above prior to faxing) ________________________________ From: David Winsemius <dwinsemius at comcast.net> Sent: Sunday, Oc...

...ogical value. Can any one tell me what is going on here? (I am using version 2.1.1 on Windows). Thanks very much, Ravi. -------------------------------------------------------------------------- Ravi Varadhan, Ph.D. Assistant Professor, The Center on Aging and Health Division of Geriatric Medicine and Gerontology Johns Hopkins University Ph: (410) 502-2619 Fax: (410) 614-9625 Email: <mailto:rvaradhan@jhmi.edu> rvaradhan@jhmi.edu -------------------------------------------------------------------------- [[alternative HTML version deleted]]

...to list the item and give a "0" to it? Or, is there a simpler way to solve this problem? Thanks for any help, Ravi. -------------------------------------------------------------------------- Ravi Varadhan, Ph.D. Assistant Professor, The Center on Aging and Health Division of Geriatric Medicine and Gerontology Johns Hopkins University Ph: (410) 502-2619 Fax: (410) 614-9625 Email: <mailto:rvaradhan@jhmi.edu> rvaradhan@jhmi.edu -------------------------------------------------------------------------- [[alternative HTML version deleted]]

...nd its SE for "regional"? The predict function will give the point estimate, but not (to my knowledge) the SE. Thank you, John John David Sorkin M.D., Ph.D. Professor of Medicine Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology and Geriatric Medicine Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 (Phone) 410-605-7119 (Fax) 410-605-7913 (Please call phone number above prior to faxing) ________________________________ From: David Winsemius <dwinsemius at comcast.net> Sent: Sunday, Oc...

...llen. The great thing about Kate is that she did so much without ever hogging the limelight. Thank you, Kate and thank you NIST! I cannot wait for UseR!2011! Best, Ravi. ____________________________________________________________________ Ravi Varadhan, Ph.D. Assistant Professor, Division of Geriatric Medicine and Gerontology School of Medicine Johns Hopkins University Ph. (410) 502-2619 email: rvaradhan at jhmi.edu

...like the x-labels of the histograms to be "X1", "X2", etc. Any help is appreciated. Best, Ravi. ---------------------------------------------------------------------------- ------- Ravi Varadhan, Ph.D. Assistant Professor, The Center on Aging and Health Division of Geriatric Medicine and Gerontology Johns Hopkins University Ph: (410) 502-2619 Fax: (410) 614-9625 Email: rvaradhan@jhmi.edu Webpage: http://www.jhsph.edu/agingandhealth/People/Faculty/Varadhan.html ---------------------------------------------------------------------------- -------- [[alter...

...mydirectory\\data.csv This does not work; the file is not found. What is the correct way to specify a path to a server Thanks, John John David Sorkin M.D., Ph.D. Professor of Medicine Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology and Geriatric Medicine Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 (Phone) 410-605-7119 (Fax) 410-605-7913 (Please call phone number above prior to faxing) Confidentiality Statement: This email message, including any attachments, is for the sole use of the inten...

If this is posted elsewhere I cannot find it. I need to perform multiple integration where some of the variables are in the bounds of the other variables. I was trying to use R2Cuba function but cannot set the upper and lower bounds. My code so far is : int <- function(y){ u2 = y[1] z2 = y[2] u1 =y[3] z1 = y[4] ff <- u1*(z1-u1)*u2*(z2-u2)*exp(-0.027*(12-z2)) return(ff) }

...not like the data I am passing to it. I do not know why. How might I correct my code? As always, Thank you, John Thank you, John John David Sorkin M.D., Ph.D. Professor of Medicine Chief, Biostatistics and Informatics University of Maryland School of Medicine Division of Gerontology and Geriatric Medicine Baltimore VA Medical Center 10 North Greene Street GRECC (BT/18/GR) Baltimore, MD 21201-1524 (Phone) 410-605-7119 (Fax) 410-605-7913 (Please call phone number above prior to faxing) [[alternative HTML version deleted]]