R: adds 3-segmented arrow between two points.

segmentarrow {diagram} | R Documentation

## adds 3-segmented arrow between two points.

### Description

Connects two points with 3 segments (default = left-vertical-right) and adds an arrowhead on one of the segments at a certain distance

### Usage

    segmentarrow(from, to, lwd = 2, lty = 1, lcol = "black",
                 arr.col = lcol, arr.side = 2, arr.pos = 0.5,
                 path = "LVR", dd = 0.5, ...)

### Arguments

`from` | coordinates (x,y) of point *from* which to draw arrow.
`to` | coordinates (x,y) of point *to* which to draw arrow.
`lwd` | line width.
`lty` | line type.
`lcol` | line color.
`arr.col` | arrow color.
`arr.side` | segment number on which arrowhead is drawn (1,2,3).
`arr.pos` | relative position of arrowhead on segment on which arrowhead is drawn.
`path` | outline of the 3 segments, default: left, vertical, right.
`dd` | length of segment arm, directed away from endpoints.
`...` | arguments passed to function straightarrow.

### Details

one segmented arrow is drawn between two points '(`from`, `to`)'

how the segments are drawn is set with `path` which can take on the values:

- "LVR": first left then vertical then right.

- "RVL": first right then vertical then left.

- "UHD": first up then horizontal then down.

- "DHU": first down then horizontal then up.

The segment(s) on which the arrow head is drawn is set with `arr.side`, which is one or more values in (1, 2, 3).

The position of the arrowhead, on the segment on which it is drawn, is set with `arr.pos`, a value between 0(start of segment) and 1 (end of segment)

The type of the arrowhead is set with `arr.type` which can take the values:

- "simple" : uses comparable R function arrows.

- "triangle": uses filled triangle.

- "curved" : draws arrowhead with curved edges.

- "circle" : draws circular head.

- "ellipse" : draws ellepsoid head

- "T" : draws T-shaped (blunt) head

see `Arrowhead` from package shape for details on arrow head.

### Value

coordinates (x,y) where arrowhead is drawn

### Author(s)

Karline Soetaert <karline.soetaert@nioz.nl>

### See Also

`straightarrow`, `bentarrow`, `curvedarrow`, `selfarrow`, `treearrow`, `splitarrow`,

`arrows`: the comparable R function,

`Arrows`: more complicated arrow function from package shape

try: demo(plotweb)

### Examples

    openplotmat(main="segmentarrow")

    pos <-cbind(A <- seq(0.2, 0.8, by = 0.2), rev(A))

    text(pos, LETTERS[1:4], cex = 2)

    segmentarrow(from = pos[1, ] + c(0, 0.05), to = pos[2, ] + c(0, 0.05),
                 arr.pos = 1, arr.adj = 1, dd = 0.1,
                 path = "UHD", lcol = "darkred")

    segmentarrow(from = pos[2, ] + c(-0.05, 0), to = pos[3, ] + c(-0.05, 0.01),
                 arr.pos = 1, arr.adj = 1, dd = 0.1,
                 lcol = "black", arr.type = "triangle")

    segmentarrow(from = pos[2, ] + c(0.05, 0), to = pos[3, ] + c(0.05, 0.01),
                 arr.pos = 0.5, dd = 0.3, path = "RVL", arr.side = 1,
                 lcol = "lightblue", arr.type = "simple")

    segmentarrow(from = pos[3, ] + c(0.05, 0), to = pos[4, ] + c(-0.05, 0.01),
                 arr.pos = 0.5, dd = 0.05, path = "RVL", lcol = "darkblue",
                 arr.type = "ellipse")

    segmentarrow(from = pos[3, ] + c(0, -0.05), to = pos[4, ] + c(0, 0.05),
                 arr.pos = 0.5, arr.side = 3, dd = 0.05, path = "DHU",
                 lcol = "darkgreen")

    segmentarrow(from = pos[3,] + c(-0.05, -0.05), to = pos[4, ] + c(0, -0.05),
                 arr.pos = 0.5, arr.side = 1:3, dd = 0.3, path = "DHU",
                 lcol = "green")

[Package diagram version 1.6.4 Index]