Frank

Frank has asked 19 questions and find answers to 409 problems.

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"I mean, a horse is a horse of course, but who rides is important."

Frank questions

fill rows downward for a column with NAs (with R base or data.table)
splitting (1:n)[boolean] into contiguous sequences
accessing Y columns with duplicated names in j of X[Y, j] merges
print the data.table package's .onAttach messages with knitr
Clean, simple function factories in R
Using data.table's .() shortcut in quoted expressions
lapply-ing with the "$" function
Efficiently computing a linear combination of data.table columns
data.table `:=` assignment expressions with dynamic inputs (existing columns) and outputs (new column names)
Saving plots in a data.table list column

Frank answers

How do I group by a variable and list by a random order in data.table?
Identify records where a given sequence of events happens within x days
Recoding groups of individuals
Alternative of slower ifelse in R data table
Replicate values of column along rows
Count all values in a column based on string in another column in R for a Venn diagram
String decomposition
R, data.table: How to assign values of some columns based on the names of other columns, which are stored in a character vector?
Can different parts of dplyr::summarize() be computed conditionally?
R rep function with for loop