m2r (version 1.0.0)

m2_path: Set path to Macaulay2 (M2)

Description

This function sets the path to external programs either by (1) passing it a character string or (2) using file.choose.

Usage

set_m2_path(path = NULL)
get_m2_path()
get_m2_con()
get_m2_procid()
get_m2_port()

Arguments

path

A character string, the path to M2

Value

An invisible character string, the path found. More importantly, the function has the side effect of setting the global m2r option "m2_path"

Details

When m2r is loaded it attempts to find M2. How it looks depends on your operating system.

If you're using a Mac or Linux machine, it looks based on your system's path. Unfortunately, R changes the system path in such a way that the path that R sees is not the same as the path that you'd see if you were working in the terminal. (You can open the Terminal app on a Mac by going to /Applications/Utilities/Terminal.) Consequently, m2r tries to guess the file in which your path is set. To do so, it first checks if your home directory (type echo ~/ in the terminal to figure out which directory this is if you don't know) for the file named .bash_profile. If this file is present, it runs it and then checks your system's path variable (echo $PATH). If it's not present, it does the same for .bashrc and then .profile. In any case, once it has its best guess at your path, it looks for "M2".

On Windows, m2r just defaults to the cloud implementation. Local M2 instances are not currently supported on Windows.

Examples

 requires Macaulay2


getOption("m2r")
get_m2_path()
set_m2_path()


## each of these functions can be used statically as well
(m2_path <- get_m2_path())
set_m2_path("/path/to/m2/directory")
get_m2_path()
set_m2_path(m2_path) # undoes example


# if you'd like to use the cloud, after you library(m2r)
# and before you use m2() type
set_m2_path(NULL)

# alternatively, if you have already been using m2, do:
stop_m2()
set_m2_path(NULL)
m2("1+1")