General
PromptBeginner5 minmarkdown
- `options(warn = n)`: -1 = ignore warnings
0 = collect (default)
0
Explore
Find agent skills by outcome
109,319 skills indexed with the new KISS metadata standard.
Showing 24 of 109,319Categories: General, Coding & Debugging, Writing & Content
General
PromptBeginner5 minmarkdown
- `options(digits = n)`: significant digits for printing (1-22
default 7). Suggestion only.
0
General
PromptBeginner5 minmarkdown
- `system.time(expr)` returns `user`
`system`
0
General
PromptBeginner5 minmarkdown
- `options(scipen = n)`: positive biases toward fixed notation
negative toward scientific. Default 0. Applies to `print`/`format`/`cat` but not `sprintf`.
0
General
PromptBeginner5 minmarkdown
- `as.numeric(diff
units = hours)` to extract numeric value in specific units.
0
General
PromptBeginner5 minmarkdown
- `difftime(time1
time2
0
General
PromptBeginner5 minmarkdown
- Explicit units: `secs`
`mins`
0
General
PromptBeginner5 minmarkdown
- `POSIXlt`: list with components `$sec`
`$min`
0
General
PromptBeginner5 minmarkdown
- `difftime` arithmetic: subtracting POSIXct objects gives difftime. Units auto-selected (secs
mins
0
General
PromptBeginner5 minmarkdown
- `POSIXct`: seconds since 1970-01-01 UTC (compact
a numeric vector).
0
General
PromptBeginner5 minmarkdown
- `seq.Date(from
to
0
General
PromptBeginner5 minmarkdown
> Non-obvious behaviors
gotchas
0
General
PromptBeginner5 minmarkdown
- `format(date
%Y)` for year
0
General
PromptBeginner5 minmarkdown
- For character sorting
depends on locale. Use `method = radix` for locale-independent fast sorting.
0
General
PromptBeginner5 minmarkdown
- Default is ascending; use `-x` for descending numeric
or `decreasing = TRUE`.
0
General
PromptBeginner5 minmarkdown
- Returns a **permutation vector** of indices
not the sorted values. Use `x[order(x)]` to sort.
0
General
PromptBeginner5 minmarkdown
- Works on multiple arguments (e.g.
`complete.cases(x
0
General
PromptBeginner5 minmarkdown
- Returns columns named after the grouping variables
with result column keeping the original name.
0
General
PromptBeginner5 minmarkdown
- Levels are sorted by default
but sort order is **locale-dependent** at creation time.
0
General
PromptBeginner5 minmarkdown
- `c()` on factors unions level sets (since R 4.1.0)
but earlier versions converted to integer.
0
General
PromptBeginner5 minmarkdown
- Only `==` and `!=` work between factors; factors must have identical level sets. Ordered factors support `<`
`>`.
0
General
PromptBeginner5 minmarkdown
- Duplicate column names allowed only with `check.names = FALSE`
but many operations will de-dup them silently.
0
Coding & Debugging
PromptBeginner5 minmarkdown
- `as.numeric(f)` returns **integer codes**
not original values. Use `as.numeric(levels(f))[f]` or `as.numeric(as.character(f))`.
0
General
PromptBeginner5 minmarkdown
- `duplicated` marks the **second and later** occurrences as TRUE
not the first. Use `fromLast = TRUE` to reverse.
0