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The data is in the attachment. What I wanna get is: , , Sex = Male Eye Hair Brown Blue Hazel Green Black 32 11 10 3 Brown 53 50 25 15 Red 10 10 7 7 Blond 3 30 5 8 , , Sex = Female Eye Hair Brown Blue Hazel Green Black 36 9 5 2 Brown 66 34 29 14 Red 16 7 7 7 Blond 4

Hi all: Here's a question about result of loglinear analysis. There're 2 factors:area and nation.The raw data is in the attachment. I fit the saturated model of loglinear with the command: glm_sat<-glm(fre~area*nation, family=poisson, data=data_Analysis) After that,I extract the coefficients: result_sat<-summary(glm_sat) result_coe<-result_sat$coefficients I find that all the

Hi all: My data:data(sleep) If I wanna calculate each group's extra,what I can do is: #method1 attach(sleep) mean(extra[group==1]) mean(extra[group==1]) #method2 result<-matrix(,0,2) g<-split(sleep,sleep$group) for(i in 1:length(g)) { result<-rbind(result,data.frame(unique(g[[i]]$group),mean(g[[i]]$extra))) } colnames(result)<-c("name","mean") But the above

Hi all: I have a question on sample size calculation of 2 groups of data. If 2 groups of data are all normal distribution, then I can use the function "n.indep.t.test.eq" from samplesize package.But if 2 groups of data are all skewed distribution, but not normal distribution,how can I calculate the sample size then? I've tried many transformation (e.g. log arcsin…) in order to

Hi all: I have a question about linear mixed model. my linear mixed model with randomized slope and intercept with interaction of time and group(g1,g2,g3): model<- glmmPQL(log10(CD4) ~ time + factor(group)+ time:factor(group), random = ~time|id) What I get is only the main and interaction of time and group.My question is: 1. How can I get the g1,g2,g3's slope respectively?In other

time1 = 2008-03-09 time2 = 2010-9-10 How to compute how many years between time1 and time2? Thanks! best [[alternative HTML version deleted]]

Hi all: I have a question about lm on t-test. data(sleep) I wanna perform t-test to test the difference between the 2 groups: I can use: t.test(extra~group) The t.test result shows that:t = -1.8608; mean1=0.75,mean2=2.33 But I still wanna use: summary(lm(extra~group)) Intercept=0.75,which is mean1,just the same as t.test. group2=1.58 means the difference of the 2 groups,so

If I have 3 groups,and for each group,I get the ratio(e.g. incidence rate). Now I wanna compare 3 ratio pairwise,and get the corresponding p values,i.e: group1 vs group2 ,p value=? group1 vs group3 ,p value=? group2 vs group3 ,p value=? Which statistical test should be used? Thanks a lot for your help. [[alternative HTML version deleted]]

Hi all: I have a dataset which contains two variables: Y and time y<-c(228,189,232,198,252,315) time<-2003:2008 How can I find out the trend(increase/decrease) of y along the time period? If I use: lm(y~time) The "lm" command treats time as natural number,but not date. So maybe "lm" isn't appropriate. Then,which function could be used? Thanks a lot for your help.

Hi all: Which function or package can perform "competitive risk model"? Thanks a lot! My best [[alternative HTML version deleted]]

Hi all,I have some questions about the covariants of regression. My target: To explore the trend of CD4 level through a period of time. Response variable: CD4 count Explanatory variable:time Also, the demology information is available,such as gender,occupation,income level... Q1,Are these variables of demology information called covariant? Q2,How can I correct the impact of

Hi all: I have a question about the sample size calculation. It's a pilot study,which includes 2 groups(low,high),3 time point(3,6,9 monthes).Each person has 3 results which according to the 3 time points.So it's a longitudinal study. I want to calculate the minimum sample size from the pilot study, but can't find the solution since the data is highly skewed and it's a

Hi all: I have 3 questions about the poisson regression of contingency table. Q1¡¢How to understand the "independent poisson process"as many books or paper mentioned? For instance: Table1 ------------------------------------------- treat caner non-cancer sum ------------------------------------------- treat1 52(57.18) 19(13.82) 71 treat2

Hi all: There's a question about glht function. My data:data_ori,which inclue CD4, GROUP,time. f_GROUP<-factor(data_ori$GROUP) f_GROUP is a factor of 3 levels(0,1,2,3) result <- lme(sqrt(CD4) ~ f_GROUP*time ,random = ~time|ID,data=data_ori) glht(result, linfct = mcp(f_GROUP="Tukey") ) Error in `[.data.frame`(mf, nhypo[checknm]) : undefined columns selected I can't

Hi all: If I have a dataframe of N columns.If I wanna get the min(or max,or mean...etc)of the whole dataframe,how to do it quickly? What I can do is only: min(data[,1:ncol(data)]) Any other suggestion? Thanks! best [[alternative HTML version deleted]]