You might be looking for the discussion from ?make.names: A syntactically valid name consists of letters, numbers and the dot or underline characters and starts with a letter or the dot not followed by a number. Names such as “.2way” are not valid, and neither are the reserved words. In the help file itself, there’s … Read more
Assuming your dataframe is mydf: mydf$task <- factor(mydf$task, levels = c(“up”, “down”, “left”, “right”, “front”, “back”))
Because the operator : has precedence over + so 1+1:3 is really 1+(1:3) (i. e. 2:4) and not 2:3. Thus, to change the order of execution as defined operator precedence, use parentheses () You can see the order of precedence of operators in the help file ?Syntax. Here is the relevant part: The following unary … Read more
You can do it all in one step and get proper labeling: > aggregate(. ~ id1+id2, data = x, FUN = function(x) c(mn = mean(x), n = length(x) ) ) # id1 id2 val1.mn val1.n val2.mn val2.n # 1 a x 1.5 2.0 6.5 2.0 # 2 b x 2.0 2.0 8.0 2.0 # 3 … Read more
Part of the answer is contained already in your question: You use data frames if columns (variables) can be expected to be of different types (numeric/character/logical etc.). Matrices are for data of the same type. Consequently, the choice matrix/data.frame is only problematic if you have data of the same type. The answer depends on what … Read more
It depends on context as to what = means. == is always for testing equality. = can be in most cases used as a drop-in replacement for <-, the assignment operator. > x = 10 > x [1] 10 used as the separator for key-value pairs used to assign values to arguments in function calls. … Read more
x <- rnorm(100,10,10) cut(x,c(-Inf,0,5,6,10,Inf))
You can get all the objects in your package with: ls(“package:caTools”) You can get all the function signatures in your package with: lsf.str(“package:caTools”)
You don’t need to wrap anything in a function – the following works a = c(T,F,NA) a %in% TRUE [1] TRUE FALSE FALSE
T and F can be re-defined, but TRUE and FALSE are reserved words and cannot be re-defined. > TRUE <- 1L Error in TRUE <- 1L : invalid (do_set) left-hand side to assignment > FALSE <- 0L Error in FALSE <- 0L : invalid (do_set) left-hand side to assignment > T <- F # yikes, … Read more