# ArrowLines: Create a Line That may have Arrows on the Ends In OpenIntroStat/openintro-r-package: Data Sets and Supplemental Functions from 'OpenIntro' Textbooks and Labs

## Description

Similar to `lines`, this function will include endpoints that are solid points, open points, or arrows (mix-and-match ready).

## Usage

 ``` 1 2 3 4 5 6 7 8 9 10 11 12``` ```ArrowLines( x, y, lty = 1, lwd = 2.5, col = 1, length = 0.1, af = 3, cex.pch = 1.2, ends = c("a", "a"), ... ) ```

## Arguments

 `x` A vector of the x-coordinates of the line to be drawn. `y` A vector of the y-coordinates of the line to be drawn. This vector should have the same length as that of `x`. `lty` The line type. `lwd` The line width. `col` The line and endpoint color. `length` If an end point is an arrow, then this specifies the sizing of the arrow. See the `length` argument in the `arrows` help file for additional details. `af` A tuning parameter for creating the arrow. Usually the default (`3`) will work. If no arrow is shown, make this value larger. If the arrow appears to extend off of the line, then specify a smaller value. `cex.pch` Plotting character size (if open or closed point at the end). `ends` A character vector of length 2, where the first value corresponds to the start of the line and the second to the end of the line. A value of `"a"` corresponds to an arrow being shown, `"o"` to an open circle, and `"c"` for a closed point. `...` All additional arguments are passed to the `lines` function.

## Author(s)

David Diez

`lsegments`, `dlsegments`, `CCP`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19``` ```CCP(xlim=c(-6, 6), ylim=c(-6, 6), ticklabs=2) x <- c(-2, 0, 2, 4) y <- c(0, 3, 0, 3) ArrowLines(x, y, col=COL, ends=c('c', 'c')) points(x, y, col=COL, pch=19, cex=1.2) CCP(xlim=c(-6, 6), ylim=c(-6, 6), ticklabs=2) x <- c(-3, 0, 1, 3) y <- c(2, 1, -2, 1) ArrowLines(x, y, col=COL, ends=c('c', 'c')) points(x, y, col=COL, pch=19, cex=1.2) CCP(xlim=c(-6, 6), ylim=c(-6, 6), ticklabs=2) x <- seq(-2, 2, 0.01) y <- x^2 - 3 ArrowLines(x, y, col=COL, ends=c('c', 'c')) x <- seq(-2, 2, 1) y <- x^2 - 3 points(x, y, col=COL, pch=19, cex=1.2) ```