search for: study1

Hi I'm trying to extract complete rows from a dataframe by group based on the maximum in a column within that group. Thus I have a dataframe: cvd_basestudy ... es_time ... _____________ study1 ... 0.3091667 study2 ... 0.3091667 study2 ... 0.2625000 study3 ... 0.3033333 study3 ... 0.2625000 __________ etc I can extract the basestudy and the max(es_time) using ddply ddply(datares_sinus_variable, .(cvd_basestudy), function(x){max(x[['es_time']])})...

...yses, I end up excluding the points R refers to, 7, 18, 26, and 105. However, my question is, how can I understand which ID numbers these points (7,18,26, and 105) are referring to? These numbers, 7,18, 26. and 105, are definitely not my study ID numbers. > Myoutput<-aov(sib~newgroup1, data=Study1) > influencePlot(Myoutput) [1] 7 18 26 105 > influence.measures(Myoutput) Influence measures of aov(formula = sib ~ newgroup1, data = Study1) : dfb.1_ dfb.nw12 dfb.nw13 dfb.nw14 dfb.nw15 dffit cov.r cook.d hat inf 33 1.70e-01 -1.33e-01 -1.53e-01 -1.56e-01 -1.52e-...

...ists of 92 rows (1 row per participant) x 186 variables. The steps of the analysis undertaken are outlined below (#). Any assistance is appreciated in relation to how to remove the missing values so the analysis is run. Feedback regarding the prior steps is also welcomed . Bob Green #Step 1 study1dat <- read.csv("c:\\study1.csv",header=T) attach (study1dat) outcome <- c(t1frq, t2frq,t3frq,t4frq) grp <- factor( rep(group, 2,length=368) ) time <- gl(4,92,length=368) subject <- gl(92,1,length=368) data.frame(subject, grp, time, outcome) # there are 3 missing values in...

...r a total 4*3*2*5 tables. I get a list of length 120 and dim 4. Noww I want to sum the tables within the level of one of the grouping variables, eg age class. How can I do? Here is an example: ttt <- by(data,list=c(age,sex,region,edu),FUN=function(x) { tto <- table(x$smoke[x$grp=="study1"]) so <- sum(tto) tte <- prop.table(table(x$smoke[x$grp=="study2"]))*so ttt <- rbind(tto,tte) ttt } Think of age as a factor with 4 levels (age category). Now a want to sum each table (observed=tto and expected=tte separately) within each age category. I should end...