Meaning of R command system("touch AAA") - r

I am watching a Machine Learning Distributed in R and this lines of code appear:
For what the teacher says, system("touch fin1") will save the document in fin1 when the process has finished.
Does anyone know where I can find documentation about such function?

Think of system as an easy way to send commands to a terminal. The touch command (at least on *unix systems) creates a file. That's all it does really.
So the individual slave sessions create a file on the system. Why would they do that? So that the master session can easily detect when the slave sessions have gotten past a certain point in their scripts. The master session is constantly looping looking to see if all of the slave sessions have successfully gotten past that first actual line in their code.
So the answer your question of "Does anyone know where I can find documentation about such function?" is to look at the documentation provided by your system. For most *unix systems you can go to a command line and enter the command man touch or man {command you're interested in} to bring up the man pages for the given command.

Related

Automating R Scripts on Mac

So I wrote my father a neat little R script that pulls financial indicators on stocks, and outputs the info to a csv...
I would like to have it set up so that the script will run automatically once a day, skipping the weekends if possible. I looked around for awhile online and it seems as though the Mac "Automator" App is what I'm looking for.
However, after reading many guides and posts (like this one https://www.r-bloggers.com/how-to-source-an-r-script-automatically-on-a-mac-using-automator-and-ical/) I cannot get it to work...
In trying to replicate what this man did above I get the error that the first path is a directory; while the latter returns stuff like "cat: Rscript: No such file or directory"
So I was wondering if anyone could recommend either any good free software that will allow me to do what I would like, or how to run an R script from the /bin/bash shell
EDIT:
The suggested solution isn't really answering my problem. The issue is making this as easy as possibly for my dad to run, that way he doesn't have to do anything, specifically use the terminal. Ideally I could just schedule a task that repeats every morning, but the cronR package requires Daemon, and the others are just command line tools
I had a similar experience.
I created an automator calendar alarm
added a Execute AppleScript Action and used the following code:
on run {input, parameters}
try
tell application "R"
activate
with timeout of 90000 seconds
cmd "source(\"Dropbox/RScripts/CV19/liibre_coronabr.R\")"
end timeout
end tell
end try
return input
end run
When you save it, just choose the date and time for it to run and select the option to repeat everyday
That's it!

Looking for a pv or dialog equivalent

I am working with network shell (nsh; bmc software) I believe it is based on zsh 4.3.4. I have written a script that connects to a list of variable solaris machines and runs numerous commands and then creates some local directories and files based off of those commands.
I am looking for a way to display the script's progress as it can take some time depending on the number of servers. I have been told by others I need to utilize pv or dialog. However, in nsh when attempting to run these commands I get "command not found." It could be a limitation of nsh as well.
As a simple example, I want to see the progress of the following:
for i in $(cat serverlist.txt)
do
nexec -i $i hostname >> hosts.txt
done
Of course my script is a lot more complex than this but I cannot seem to get it working correctly as pv and dialog are not available. Also I know I should be using read -r to truncate the file, but appears not to work correctly either.

Refresh R console without quitting the session?

I usually open the R console all day long, but sometimes I need to clean my history and my workspace's background so that I can test functions or load new data.
I'm wondering whether there is an easier way to use a command line in .Rprofile so that I can refresh the R console without quitting or rebooting my current session.
What I have usually done for this is to q() without saving and then start R again and clean the History. I think somebody here might be able to give me some better suggestions.
Thanks in advance.
For what concerns history, in UNIX-like systems (mine is Debian) this command refreshes it
loadhistory("")
However, as said in comments, loadhistory seems to be platform-dependent.
Check your ?loadhistory if present on your platform. Mine says:
There are several history mechanisms available for the different
R consoles, which work in similar but not identical ways. There
are separate versions of this help file for Unix and Windows.
The functions described here work on Unix-alikes under the
readline command-line interface but may not otherwise (for
example, in batch use or in an embedded application)

Couple of basic questions about Julia on Windows

I run Julia on Windows with the julia.bat file given in the zip archive. I have a couple of basic questions. This launches a DOS console.
When typing a plot() command Julia returns plot not defined. How to use the plot() function ? Is there a graphical interface available ?
When typing help I get:
What does it mean ?
There is also the launch-julia-webserver.bat file in the zip archive. When running this file two DOS windows open but nothing else happens. What can we do with this file and how ?
By the way I do not find any documentation answering such basic questions... of course if you know where to find such a documentation it would be an ideal answer.
To answer your immediate question, help is implemented as a function, and functions must be called with parentheses. Try help(), or to get help for a particular function in the standard library supply it as an argument; i.e., help(help).
When you enter a function name without the parentheses, the default is to print all of the implementations with their argument types.
The main Julia documentation is available online at http://docs.julialang.org/. We also have a mailing list at https://groups.google.com/forum/#!forum/julia-dev.
The webserver is pretty rough, especially on Windows. You should be able to open up http://localhost:2000/ with it running and access a web-based command environment. But you'll probably just want to stick to the normal command line.
Another contributor highlighted the response to help as a potential issue for new users and we've opened a bug on it at https://github.com/JuliaLang/julia/issues/1320. It's a new language and there's still plenty of rough edges, so thanks for helping us file those down!
To use launch-julia-webserver.bat, after you double-click it and the two DOS windows open, one of them should say "Connect to http://localhost:2000/ for the web REPL". If you open a web browser to http://localhost:2000/, you should be greeted with a welcome page that asks for your name and a session name.

Where is the rc.boot script file in AIX? Could I access & modify it under the running environment?

I want to pick up the rc.boot script file & modify something in AIX system.
How to find it out? Thanks
I would suggest not to modify the rc.boot script on AIX.
Not very many services are started at that point in the boot process - very easy to introduce something that may result in the system not fully booting.
May be replaced by updates from IBM without warning - thus wiping out your changes.
Follow the method from comp.unix.aix . This set-up or something similar to it has been used at all the AIX shops I have worked at over the last 20 years. I currently use this on 50+ servers (except it is called rc.server instead of rc.local). Placing it in the /etc/inittab as illustrated (after rc.nfs) ensures that NFS services are up and running when your script(s) are run.
Cheers
I Googled rc.boot and the first result was documentation from IBM.
It is located at /sbin/rc.boot.

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