What is the difference between require() and library()? 8 s 8 In addition to the good advice already given, I would add this: It is probably best to avoid using require() unless you actually will be using the value it returns e.g in some error checking loop such as given by thierry. In most other … Read more
I want to look at the source code for a function to see how it works. I know I can print a function by typing its name at the prompt: > t function (x) UseMethod(“t”) <bytecode: 0x2332948> <environment: namespace:base> In this case, what does UseMethod(“t”) mean? How do I find the source code that’s actually … Read more
I tried to install a package, using install.packages(“foobarbaz”) but received the warning Warning message: package ‘foobarbaz’ is not available (for R version x.y.z) Why doesn’t R think that the package is available? See also these questions referring to specific instances of this problem: My package doesn’t work for R 2.15.2 package ‘Rbbg’ is not available … Read more
I would like to plot y1 and y2 in the same plot. x <- seq(-2, 2, 0.05) y1 <- pnorm(x) y2 <- pnorm(x, 1, 1) plot(x, y1, type = “l”, col = “red”) plot(x, y2, type = “l”, col = “green”) But when I do it like this, they are not plotted in the same … Read more
When I convert a factor to a numeric or integer, I get the underlying level codes, not the values as numbers. f <- factor(sample(runif(5), 20, replace = TRUE)) ## [1] 0.0248644019011408 0.0248644019011408 0.179684827337041 ## [4] 0.0284090070053935 0.363644931698218 0.363644931698218 ## [7] 0.179684827337041 0.249704354675487 0.249704354675487 ## [10] 0.0248644019011408 0.249704354675487 0.0284090070053935 ## [13] 0.179684827337041 0.0248644019011408 0.179684827337041 ## [16] … Read more
Apparently, folk have figured out how to make xkcd style graphs in Mathematica and in LaTeX. Can we do it in R? Ggplot2-ers? A geom_xkcd and/or theme_xkcd? I guess in base graphics, par(xkcd=TRUE)? How do I do it? As a first stab (and as much more elegantly shown below) in ggplot2, adding the jitter argument … Read more
I have a plot where the x-axis is a factor whose labels are long. While probably not an ideal visualization, for now I’d like to simply rotate these labels to be vertical. I’ve figured this part out with the code below, but as you can see, the labels aren’t totally visible. data(diamonds) diamonds$cut <- paste(“Super … Read more
Overview I’m relatively familiar with data.table, not so much with dplyr. I’ve read through some dplyr vignettes and examples that have popped up on SO, and so far my conclusions are that: data.table and dplyr are comparable in speed, except when there are many (i.e. >10-100K) groups, and in some other circumstances (see benchmarks below) … Read more
What are the differences between the assignment operators = and <- in R? I know that operators are slightly different, as this example shows x <- y <- 5 x = y = 5 x = y <- 5 x <- y = 5 # Error in (x <- y) = 5 : could not … Read more
I have a data frame and some columns have NA values. How do I replace these NA values with zeroes? 26 s 26 See my comment in @gsk3 answer. A simple example: > m <- matrix(sample(c(NA, 1:10), 100, replace = TRUE), 10) > d <- as.data.frame(m) V1 V2 V3 V4 V5 V6 V7 V8 V9 … Read more
