R: North-South Weather Vane Arrow

NSarrow {GEOmap} | R Documentation

## North-South Weather Vane Arrow

### Description

Add north-south weather vane arrow figure

### Usage

    NSarrow(x = NULL, y = NULL, R = 1, col.arrow = 1, col.N = 1,
    col.circ = 1, rot = 0, PMAT = NULL)

### Arguments

`x` | X-location vector, if list, include both x and y values
`y` | Y-location vector, not needed if x is a list
`R` | radius, in plot coordinates
`col.arrow` | color for arrow, default="black"
`col.N` | color for N symbol
`col.circ` | color for circle
`rot` | rotation angle, degrees
`PMAT` | projection matrix, output of persp

### Details

The location list should have 2 values for x and y each, the second value for y determines the radius R if it is not provided. The first element of y is the center of the weather vane. If no x-list is provided, the interactive locator function is invoked and a list is returned for future work.

### Value

`x` | x-location
`y` | y-location

### Author(s)

Jonathan M. Lees<jonathan.lees@unc.edu>

### See Also

zebra

### Examples

    plot(c(1:10), c(1:10), type='n')

    x=c(2,2)
    y = c(8,9)

    NSarrow(list(x=x, y=y))

    ##### move over and repeat, with rotation of 25 degrees west

    x=c(5,5)
    y = c(8,9)

    NSarrow(list(x=x, y=y), rot=25)

[Package GEOmap version 2.4-0 Index]