similar to: Coercing by/tapply to data.frame for more than two indices?

Dear List, why does this not work? df <- data.frame(var1 = c(3,2,1), var2 = c(6,5,4), var3 = c(9,8,7), fac = c('A', 'A', 'B')) tapply(cbind(df$var1, df$var2, df$var3), df$fac, mean) Thank you, Stefan

Dear List, I have Multi-level Data i= Indivitual Level g= Group Level var1= First Variable of interest var2= Second Variable of interest and I want to count the frequency of "var1" and "var2" on the group level. I found a way, but there must be a much simpler way. data.ml <- data.frame(i=c(1:8),g=as.factor(c(1,1,1,2,2,3,3,3)),var1=c(3,3,3,4,4,4,4 ,4),

Dear all, I'm wanting to do a series of comparisons among 4 categorical variables: a <- aggregate(y, list(var1, var2, var3, var4), sum) This gets me a very nice 2-dimensional data frame with one column per variable, BUT, as help for aggregate says, <<empty subsets are removed>>. I don't see in help(aggregate) how I can change this. In contrast, a <- tapply(y,

Previously, I posed the question pasted down below to the list and received some very helpful responses. While the code suggestions provided in response indeed work, they seem to only work with *very* small data sets and so I wanted to follow up and see if anyone had ideas for better efficiency. I was quite embarrased on this as our SAS programmers cranked out programs that did this in the blink

Hi, this is a simple question I have this data.frame: > test <- data.frame(var1=c(1,1,1,1,1,1),var2=c("a","a","b","c","d","e"),var3=c("a1","a1","b1","a1","c1","d1")) > test var1 var2 var3 1 1 a a1 2 1 a a1 3 1 b b1 4 1 c a1 5 1

Suppose I have a dataframe as follows: dat <- data.frame(id = c(1,1,2,2,2), var1 = c(10,10,20,20,25), var2 = c('foo', 'foo', 'foo', 'foobar', 'foo')) Now, if I were to subset by id, such as: > subset(dat, id==1) id var1 var2 1 1 10 foo 2 1 10 foo I can see that the elements in var1 are exactly the same and the elements in var2 are exactly

Hello, See my problem below. a<-data.frame(c("s","c","c","n","n","n"),c(rep(1,3),rep(2,3)),c(rep(2,3),rep(1,3)),c("01/01/1999","10/02/2000","13/02/2000","11/02/2000","15/02/2000","23/02/2000"))

I need to do a somewhat complex rearrangement of an existing dataframe that involves an "on-the-fly" conditional summary as well. I've tried to make the example as simple as possible. Code to produce the object being acted on is at the end of the message. I hope this isn't too much for a single posting. Any guidance will be much appreciated. The input example looks like

Hi listers, I have a simple doubt... I need to manipulate the data base as: var1 var2 7 0.1 7 0.1 8 0.12 10 0.15 12 0.18 20 0.31 I would like to aggregate the equal cases as var1 making the sum of var2... I would get... var1 var2 7 0.2 8 0.12 10 0.15 12 0.18 20 0.31 Thanks in advance, Marcio -- View this message in context:

Hello, and thanks in advance. I have a data.frame from which I want to count observations that occur on each day and determine the mean and std.error of said counts. For instance: x<-split(my.df, my.df$julian.days) Although I'm still in my R learning infancy I am under the impression that x is a list of data.frames subsetting my.df by group (i.e.,julian.day) where day 1:366 are

Can somebody tell me how to do the equivalent of a pivot table in R ? For example, if I have : var1 var2 var3 a x 10 b y 20 a z 10 b z 20 a z 10 b z 20 I could have : x y z a 1 0 2 b 0 1 2 where entries in the table are counts of var3.

Hi folks, I have a dataframe df.vars with the follwing structure: var1 var2 var3 group Group is a factor. Now I want to standardize the vars 1-3 (actually - there are many more) by class, so I define z.mean.sd <- function(data){ return.values <- (data - mean(data)) / (sd(data)) return(return.values) } now I can call for each var z.var1 <- by(df.vars$var1, group,

I have a dataset with three variables: date, var1, var2 How can I calculate the correlation, by date, between var1 and var2? e.g. date var1 var2 1/1/2001 5 4 1/1/2001 8 5 1/1/2001 9 7 2/1/2001 7 2 2/1/2001 2 1 2/1/2001 4 6 3/1/2001 3 5 3/1/2001 4 3 3/1/2001 6 9 3/1/2001 7 -1 the results I want: 1/1/2001

hi dear R users, I'm a newbie with R and excuse me if my question is stupid ... but i've read lot of documentation and I don't know how to do. I have a dataset like x y var1 var2 2 4 10 50 3 3 20 70 3 2 50 68 4 5 34 42 5 3 10 23 7 8 23 42 7 3 23 34 [...] And I need to produce grids like : y\x ]0-2] ]2-4]

I have a dataframe called "data" with 5 records (in rows) each of which has been scored on each of many variables (in columns). Five of the variables are named var1, var2, var3, var4, var5 using headers. The other variables are named using other conventions. I can create a new variable called var6 with the value 15 for each record with this code: > var6=var1+var2+var3+var4+var5

Hi, I am using R 1.9.1 on on i686 PC with SuSE Linux 9.0. I have a data.frame, e.g.: > myData <- data.frame( var1 = c( 1:4 ), var2 = c (5:8 ) ) If I add a new column by > myData$var3 <- myData[ , "var1" ] + myData[ , "var2" ] everything is fine, but if I omit the commas: > myData$var4 <- myData[ "var1" ] + myData[ "var2" ] the name

Hi all, I have been trying to solve this problem and have had no luck so far. I have numeric vectors VAR1, VAR2, and VAR3 which I am trying to cbind. I also have a character vector "VAR1,VAR2,VAR3". How do I manipulate this character vector such that I can input a transformed version of the character vector into cbind and have it recognize that I'm trying to refer to my numeric

Buenas noches Javier y José, Estoy en contra de usar attach(), asi que propongo la siguiente alternativa con with(): # paquete require(epicalc) # los argumentos en ... pasan de epicalc:::cc # ver ?cc para mas informacion foo <- function(var1, var2, var3, ...){ or1 <- cc(var1, var2, ...) or2 <- cc(var1, var3, ...) list(or1 = or1, or2 = or2) } # datos x <-

I would like to know how to turn a variable into a string. I have tried as.symbol and as.name but it doesnt work for what I'd like to do Essentially, I'd like to feed the function below with two variables. This works fine in the bit working out number of elements in each variable. In the print(sprintf("OK with %s and %s\n", var1, var2)) line I would like var1 and var2 to be

Hallo Is there an elegant way to do the following: Dataset consists of 2 variables: var1: some measurements, and var2: a grouping variable with two values, 1 and 2. There are (say) 10 measurements from group 1 and 15 measurements from group 2. The idea is to study the permutation distribution of mean(group 1) * mean(group2). One way would be to permute 1s and 2s and select the corresponding