similar to: Factor tutorial?

I noticed that when I fit a linear model using 'lm' there is an attribute called "factors" that is added to the "term". It doesn't seem to appear for 'model.matrix', just 'lm'. I have been unable to find where it gets constructed or what it means? It looks like a two dimensional array that I may be able to use so I would just like to get some

Thanks to Marc Schultz I found the documentation on the "factors" attribute under ?term.object. It stats: factors: A matrix of variables by terms showing which variables appear in which terms. The entries are 0 if the variable does not occur in the term, 1 if it does occur and should be coded by contrasts, and 2 if it occurs and should be coded via dummy

I noticed that the text() command adds text to a plot. Is there a way to either make the plot blank or add text to a "blank sheet". I would like to "plot" a page that contains just text, no plot lines, labels, etc. Suggestions? Kevin [[alternative HTML version deleted]]

Doing ?factor I get: x a vector of data, usually taking a small number of distinct values. levels an optional vector of the values that x might have taken. The default is the set of values taken by x, sorted into increasing order. So if I do: factor(letters[1:20],level=seq(1:20) [1] <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA>

Given a Date object or simply a year is there an R function to tell me if the it is a leap year or not? I was hoping for something like 'is.leapyear'. I probably can build my own function (year divisible by 4 etc.) but I would rather use an existing function if it is available. Thank you. Kevin

Why does: (shape/scale) * (1:365/scale)^(shape - 1) return a vector of numbers but calling a function hasard(1:365,shape,scale) defined like: hazard <- function(x,shape,scale) { return (shape/scale) * (x/scale)^(shape - 1) } Only return a single value? It is like x becomes a single value passed as an argument. Thank you. Kevin

I had a question about the basic power functions in R. For example from the R console I enter: -1 ^ 2 [1] -1 but also -1^3 [1] -1 -0.1^2 [1] -0.01 Normally pow(-1, 2) return either -Infinity or NaN. Has R taken over the math functions? If so I would think that -1^2 is 1 not -1 and -0.1^2 is 0.01 not -0.01. Thank you. Kevin

I am trying to upgrade to R 2.14 from R 2.13.1 I have compied all the libraries from the 'library' directory in my existing installation (2.13.1) to the installed R 2.14. Now I want to uninstall the old installation (R 2.13.1) and I get the error: Internal Error: Cannot find utCompiledCode record for this version of the uninstaller. Any ideas? Kevin [[alternative HTML

I am running R 2.9.2 and creating a PDF that I am trying to open with Adobe Reader 9.2 but when I try to open it the reader responds with "There was an error opening this document. The file is damaged and cannot be repaired.: I am using the R command(s): pdf(file="cat.pdf", title="Historical Sales By Category") for(j in 1:length(master)) { d <-

This may be a begining question. If so, please bear with me. If I have some data that based on the historgram and other plots it "looks" like a beta distribution. Is there a function or functions within R to help me determine the model parameters for such a distirbution? Similarily for other "common" distirbutions, Poisson(lambda), Chi-Square(degrees of freedom, chi-square

I give up. Maybe it is my search (Windows) but I cannot seem to find the definition of the F77_CALL or F77_NAME macros. Either there are too many matches or the search just doesn't find it. For example where is the source for: F77_CALL(dpotri) ? Thank you. Kevin

I have a command that reads in some data: x <- read.csv("Sales2007.dat", header=TRUE) Then I try to organize the data: sc <- split(x, list(x$Category, x$SubCategory), drop=TRUE) Then I want to iterate through the data. I was able to get the following to run on the R console: for(i in 1:length(sc)) { sum(sc[[i]]$Quantity) } But notiing is primted on the console. I find

Hello, I asked a question about what the most likely process to follow if after a time-series fit is performed the residuals are found to be non-normal. One peron responded and offered to help if I supplied a sample data set. Unfortunately now that I have a sample I have lost the emai addressl. If you are that person or have some ideas please email me back at rkevinburton at charter.net. Thank

I am trying to sort a list and the data is obiously not in the right format. I am trying: x <- list() x[["A"]] <- 1 x[["B"]] <- 2 order(x) But am getting: Error in order(x) : unimplemented type 'list' in 'orderVector1' How should I change the list so that it can be sorted? What kinds of objects (classes of objects) can be sorted? Thank you. Kevin

I am having a hard time understanding just what 'sweep' does. The documentation states: Return an array obtained from an input array by sweeping out a summary statistic. So what does it mean "weeping out a summary statistic"? Thank you. Kevin

Simple question: Why doesn't the following work? Or what 'R' rule am I missing? tclass <- "Testing 1 2 3" if(tclass == "Testing 1 2 3") { cat("Testing", tclass, "\n") } else { cat(tclass, "\n") } I get an error 'else' is unexpected. Thank you. Kevin

I have two vectos (list) that represent a years of data. Each "row" is represented by the day of year and the quantity that was sold for that day. I would like to form a new vector that is the difference between the two years of data. A sample of A (and similarly B) looks like: > A[1:5,] DayOfYear x 1 1 1429 2 2 3952 3 3 3049 4 4 2844 5 5

Can someone enlighten me on why the following doesn't work? setwd('C:/Temp/R') d <- rep(1:53,2) (s <- ts(d, frequency=53, start=c(2000,10))) n <- length(s) k <- n%/%3 for(i in (n-k):n) { st <- c(start(s)[1] + (start(s)[2] + i)%/%frequency(s), (start(s)[2] + i) %% frequency(s)) ed <- c(start(s)[1] +

I have a list of data.frames > str(bins) List of 19217 $ 100026:'data.frame': 1 obs. of 6 variables: ..$ Sku : chr "100026" ..$ Bin : chr "T149C" ..$ Count: int 108 ..$ X : int 20 ..$ Y : int 149 ..$ Z : chr "3" $ 100030:'data.frame': 1 obs. of 6 variables: ....... As you can see one 'column' is

In browsing the source I see the following construct: res <- switch(type, working = , response = r, deviance = , pearson = if (is.null(object$weights)) r else r * sqrt(object$weights), partial = r) I understand that 'switch' will execute the code that is matched by its corresponding string value (in this case 'type'). What I don't