similar to: ANOVA

Hi All, I have a file with two columns, the first column has the names of the patients and the second column has the age. I am looking into creating an output file that looks like 1-10 10-20 etc Eric Chris Bob mat Andrew Suzan Where each column has the name of the patients in a given age category that is displayed in the header. For example in the output, the first

Hi, I would like to use a weighted lm model to reduce heteroscendasticity. I am wondering if the only way to generate the weights in R is through the laborious process of trial and error by hand. Does anyone know if R has a function that would automatically generate the weights need for lm? Thanks, -- Tom [[alternative HTML version deleted]]

Hi , Does any one know how to split a character vector , I have a vector X that looks like this and each row has 3 characters X ASK DGH ASG AUJ FRT I would like to split the vector into 3 vectors that look like this X1 X2 X3 A S K D G H A S G A U J U R T thanks -- View this message in context: http://www.nabble.com/How-to-split-a-character-vector-into-3-vectors-tp21939492p21939492.html

Hi, I need to correct for ar(1) behavior of my residuals of my model. I noticed that there are multiple gls models in R. I am wondering if anyone has experience in choosing between gls models. For example, how should one decide whether to use lm.gls in MASS, or gls in nlme for correcting ar(1)? Does anyone have a preference? Any advice is appreciated! Thanks, -- Tom [[alternative HTML

I want to know how accurate are the p-values when you do linear regression in R? I was looking at the variable x3 and the t=10.843 and the corresponding p-value=2e-16 which is the same p-value for the intercept where the t-value for the intercept is 48.402. I tried to calculate the p-value in R and I got 0 x<-2*(1-pt(10.843,2838)) > x [1] 0 > G<-lm(y~x1+x2+x3+x4+x5) >

I would like to merge ?data1 ?that contains 100 unique ID?s with another data set ?data 2? with 150 ID?s and the age of those individuals ( the ID in data1 is a subset of the ID in data 2) I would like to merge these data1 with data2 and have the result of the merge to have the ID ordered as in data1. Can this be done in R? -- View this message in context:

I have a problem with ifelse(), I do not understand how it works. > X<-c(2,2,1,1,0,0) > str(X) num [1:6] 2 2 1 1 0 0 > Y<-ifelse(X>0,1,0) > Y [1] 1 1 1 1 0 0 > Can some one explain what is going on, I do not understand what ifelse is doing in this case. Can someone explain the output Y. Thanks -- View this message in context:

Hi All, I always have a problem with write.csv when I want the column names to be ignored, when I specify col.names=F, I get a header of V1 V2 V3 V4 etc. for example I tried write.csv(mydata, file="data.csv", quote=FALSE, row.names=F, col.names=F) Warning message: In write.csv(mydata, file = "data.csv", quote = FALSE, : attempt to set 'col.names' ignored >

Hi All, I have a character vector with naems of cities in the us. I need to extract the number that appear after the word "New York", for example, x<-c("P Los Angeles44AZ", "P New York722AZ", "K New York20") I want the results to be 722, 20 cab I use the grep function, if so how? I appreciate your help, thanks, -- View this message in context:

Hi, I'm trying to figure out how anova works in R by translating the examples in Sokal And Rohlf's (1995 3rd edition) Biometry. I've hit a snag with planned comparisons, their box 9.4 and section 9.6. It's a basic anova design: treatment <- factor(rep(c("control", "glucose", "fructose", "gluc+fruct",

Hi All, I was wondering if there is anything that breaks a loop in R. For example, For (k in 1:100) For ( i in 1:10){ If ( condition ){ Break the inner loop } } } In the above case, if the program runs the if statement, then I want the inner loop for (i in 1:10) to stop looping and skip the rest of the program. Thanks for your help -- View this message in context:

Hi All, I was wodering if it is possible to increase the precision using R. I ran the script below in R and MAPLE and I got different results when k is large. Any idea how to fix this problem? thanks for your help for (k in 0:2000){ s=0 for(i in 0:k){ s=s+((-1)^i)*3456*(1+i*1/2000)^3000 } } -- View this message in context:

Hi All, I have a dataset that I would like to split based on : or ? ( the data file is tab delimited) for example: Ny:23-45 AC BA:88-91 DB KJ:21-13 PA And I would like the data to be splitted and the final results look like NY 23 45 AC BA 88 91 DB KJ 21 13 PA I would like to have the resulting data as a data frame so each column is a variable. Thanks, -- View this message in context:

Hi, I am new to R so forgive me if the following query is somewhat simple.  I have a small tab-separated file with n records of glucose values, one record per day, seven measurements per day. It looks like this: date    sober    no    vm    nm    va    na    vs 20091229    NA    6.8    NA    2.7    11.7    2.7    6.2 I'd like to make a graph on which the glucose day curves are plotted

Hi All, I have a column that contains values between 0 and 1. I would like to make a table that consists of the number of elements in each category. For example , how many elements have values between 0 and 0.1, 0.1 to 0.2, 0.2 to 0.3,etc??..0.9 to 1. Is there an easy way to do this? Thanks -- View this message in context:

Greetings R users, I am trying to renumber my groups within the file shown below. The groups are currently set as 8,9,10,etc. I would like to renumber this as 1,2,3,etc. I have searched the help files and only come across using the rownames to renumber the values but I need to match values. Any assistance is always appreciated, Regards, Charles structure(list(Group = structure(c(1L, 1L, 1L,

Dear all, I have the following output generated by linear regression. Since there is only one regression intercept and one slope for one set of data, what is the meaning of std. error for intercept and that of slope? Thanks in advance. Sincerely, Minghua > data(thuesen) > attach(thuesen) > lm(short.velocity~blood.glucose) Call: lm(formula = short.velocity ~ blood.glucose)

Hello, I've been fitting a random effects model using nlme to some data, but I am discovering that the variation in my random effect is very small. As a result, I would like to replace it as a fixed effect (i.e. essentially fit the same model but with no random effect). As I understand it I could do this using nls(), but I'm using a number of options such as weights = varPower()

Hi all, I would like to test the homoegeneity of variances between several linear model for some analysis of covariance. It seems that the Bartlett's test is a good test to use but I am having problem using with linear model and I cannot find any examples on the internet. There are some examples for comparisons of variances but not linear models. If I take the hellung data set, which is

Hi All, I am looking into merging 3 data sets I know how to do that by merging data1 with data2 and then merging the result with data 3. I was wondering if it can be done all at once so I tried, M<-merge(data1,data2,data3, by=?ID?) It does not work! Any ideas? -- View this message in context: http://www.nabble.com/merging-3-data-sets-at-once-tp17658873p17658873.html Sent from the R help