General
PromptBeginner5 minmarkdownQuality: 28
- tryCatch unwinds the call stack — handler runs in the calling environment
not where the error occurred. Cannot resume execution.
0
Explore
Find agent skills by outcome
130,759 skills indexed with the new KISS metadata standard.
Showing 24 of 130,759Categories: Data & Insights, Coding & Debugging, Cursor-rules, Data, Openclaw, General
General
PromptBeginner5 minmarkdownQuality: 24
- `tryCatch(expr
error = function(e) e)` returns the error condition object.
0
General
PromptBeginner5 minmarkdownQuality: 24
- `Position(f
x) returns the index of the first match (like Find` but returns position
0
General
PromptBeginner5 minmarkdownQuality: 28
- lengths(x) returns the length of each element of a list. Equivalent to `sapply(x
length)` but faster (implemented in C).
0
General
PromptBeginner5 minmarkdownQuality: 24
- `Find(f
x) returns the first element where f(elem) is TRUE. Find(f
0
General
PromptBeginner5 minmarkdownQuality: 24
- `Map(f
...) is a simple wrapper for mapply(f
0
General
PromptBeginner5 minmarkdownQuality: 24
- `Filter(f
x) keeps elements where f(elem) is TRUE. Unlike x[sapply(x
0
General
PromptBeginner5 minmarkdownQuality: 24
- `Reduce(f
x
0
General
PromptBeginner5 minmarkdownQuality: 24
- `Reduce(f
x
0
General
PromptBeginner5 minmarkdownQuality: 24
- `Reduce(f
x) applies binary function f cumulatively: Reduce(+
0
General
PromptBeginner5 minmarkdownQuality: 24
- `do.call(fun
args_list) — args` must be a list
0
Data
PromptBeginner5 minmarkdownQuality: 24
- Useful pattern: `do.call(rbind
listofdfs)` to combine a list of data frames.
0
General
PromptBeginner5 minmarkdownQuality: 24
Non-obvious behaviors
gotchas
0
General
PromptBeginner5 minmarkdownQuality: 24
- Use stop()
warning()
0
General
PromptBeginner5 minmarkdownQuality: 24
- `with(df
expr) avoids repeating df$` everywhere
0
General
PromptBeginner5 minmarkdownQuality: 28
- misc-utilities.md — Read when: do.call behaves differently than direct call
need Reduce/Filter/Map
0
General
PromptBeginner5 minmarkdownQuality: 28
- dates-and-system.md — Read when: Date/POSIXct conversion gives wrong day
time zones cause off-by-one
0
Data
PromptBeginner5 minmarkdownQuality: 28
- io-and-text.md — Read when: read.table silently drops data or misparses columns
regex behaves differently than expected
0
Data
PromptBeginner5 minmarkdownQuality: 28
- visualization.md — Read when: par settings reset unexpectedly
layout/mfrow interaction is confusing
0
Data
PromptBeginner5 minmarkdownQuality: 28
- statistics.md — Read when: hypothesis test gives surprising result
need to choose correct p.adjust method
0
Data
PromptBeginner5 minmarkdownQuality: 28
- data-wrangling.md — Read when: subsetting returns wrong type
apply on data frame gives unexpected coercion
0
General
PromptBeginner5 minmarkdownQuality: 24
- modeling.md — Read when: formula syntax is confusing (I()
* vs :
0
General
PromptBeginner5 minmarkdownQuality: 24
For deeper coverage
read the reference files in references/:
0
General
PromptBeginner5 minmarkdownQuality: 24
Non-obvious behaviors
surprising defaults
0