chronosphere: shaper – R documentation

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shaper

Code snippets defining ranges based on points located on a plot

Description

The function returns snippets of code that you can paste in your script after you select points on a plot. Useful for defining areas on a map. The default methods assume that you will first click in the bottom left and then in the bottom right corner.

Usage

shaper(f = "p", n = 2, round = 2, ...)

Arguments

`f`	(`character`) A single letter value specifying for which function's arugment format you want to get parameters. `"p"` is for `plot`, `"r"` is for `rect`, `"s"` is for `segments`. `"e"` returns a call to create an `extent` class object from the package `raster`. `"m"` will return code to define a 2 column matrix.
`n`	(`integer`) The number of points to request.
`round`	(`integer`) Number of digits to round to, can be two values, first is for `x` second for `y`.
`...`	arguments passed to the `locator` function

Value

For certain methods ("m" and "e") the function returns a matrix or extent class object if the function output is assigned to a name.

Examples

# plot something
data(dems)
mapplot(dems[1], col="earth")
# click 5 times to get the long-lat coords of 5 points
# shaper("m",5)
# example output:
mat <- matrix(c(                
  -2.89, 31.55,
  3.32, 26.99,
  21.17, 17.87,
  33.6, 11.03,
  5.65, 19.39
), ncol=2, byrow=TRUE)
#plot them 
points(mat)

chronosphere

Earth System History Variables

v0.4.1

CC BY 4.0

Authors

Adam T. Kocsis, Nussaibah B. Raja

Initial release

2021-04-16