Find agent skills by outcome

- `dev.copy(pdf

file = plot.pdf)` followed by `dev.off()` to save current plot.

- `persp(x

- `rect(xleft

ybottom

Coding & Debugging

- `arrows`: `code = 1` (head at start)

`code = 2` (head at end

- For `image`

`x` and `y` specify **cell boundaries** or **midpoints** depending on context.

- `contour(x

- Plots columns of one matrix against columns of another. Recycles `col`

`lty`

Data

- Formula interface: `pairs(~ var1 + var2 + var3

data = df)`.

- `panel` function receives `(x

- First argument can be an expression in `x` or a function: `curve(sin

- `mtext`: `line` argument positions text in margin lines (0 = adjacent to plot

positive = outward). `adj` controls horizontal position (0-1).

- Read-only parameters: `cin`

`cra`

- `axis(side

- `mgp = c(3

- `usr` with log scale: contains log10 of the coordinate limits

not the raw values.

- `las`: 0 = parallel to axis

1 = horizontal

> Non-obvious behaviors

gotchas

- `mai` (inches)

`mar` (lines)

- Setting `mfrow`/`mfcol` resets `cex` to 1 and `mex` to 1. With 2x2 layout

base `cex` is multiplied by 0.83; with 3+ rows/columns

- Lognormal: `meanlog` and `sdlog` are mean/sd of the log

not of the distribution itself.

Data

- Formula interface: `cor.test(~ x + y

data = df)` — note the `~` with no LHS.

- Returns `$estimate`

`$p.value`

- **`n` argument in `r*()` functions**: if `length(n) > 1`

uses `length(n)` as the count

- Beta: `shape1` (alpha)

`shape2` (beta) — no `mean`/`sd` parameterization.