trackViewer (version 1.8.4)

addArrowMark: Add arrow mark to the figure at a given position

Description

A function to add arrow mark for emphasizing peaks

Usage

addArrowMark(pos=grid.locator(), label=NULL, angle=15,  length=unit(.25, "inches"), col="red", cex=1, quadrant=4, type="closed", vp=NULL)

Arguments

pos

A unit object representing the location of arrow mark to be placed at current viewport. Default is the value of grid.locator, which will get the location of the mouse click.

label

A character or expression vector.

angle

A parameter passed into grid::arrow function. The angle of arrow head in degrees (smaller numbers produce narrower, pointier arrows). Essentially describes the width of the arrow head.

length

A parameter passed into grid::arrow function. Aunit specifying the length of the arrow head.

col

color of the arrow

cex

Multiplier applied to fontsize

quadrant

the direction of arrow, 1: to bottomleft, 2: to bottomright, 3: to topright, 4: to topleft

type

A parameter passed into grid::arrow function. One of "open" or "closed" indicating whether the arrow head should be a closed triangle.

vp

A Grid viewport object. It must be output of viewTracks

Value

invisible x, y position value.

See Also

See Also as addGuideLine, arrow

Examples

    grid.newpage()
    addArrowMark(list(x=unit(.5, "npc"), 
                      y=unit(.5, "npc")), 
                 label="label1",
                 col="blue")
    ## how to get the position by mouse click
    if(interactive()){
        pos <- addArrowMark(label="byClick")
        addArrowMark(pos, label="samePosAsAbove")
    }