Install from R command line a package source on disk

install.packages("c:/Users/utsav/Source/Repos/crosstalk/", repos = NULL, type="source")

Rstudio does not see rJava under Ubuntu 12.04

library(rJava) in Rstudio gives the error :

Error : .onLoad failed in loadNamespace() for 'rJava', details:
  call: dyn.load(file, DLLpath = DLLpath, ...)
  error: unable to load shared object '/home/anh/Rlibs/rJava/libs/rJava.so':
  libjvm.so: cannot open shared object file: No such file or directory 

Solution : add
export LD_LIBRARY_PATH=/usr/lib/jvm/java-8-oracle/lib/amd64:/usr/lib/jvm/java-8-oracle/jre/lib/amd64/server

into /etc/bash.bashrc , then run

. /etc/bash.bashrc

then run

sudo R CMD javareconf

then restart Rstudio

Git credential store

If your online git server does not allow ssh (like Microsoft Visual Studio Online), you can store git credentials in a file (not safe)

git config credential.helper store

see https://git-scm.com/docs/git-credential-store

plot multiple columns on the same graph in R with reshape2 and ggplot2

http://stackoverflow.com/questions/9531904/plot-multiple-columns-on-the-same-graph-in-r

s <- span=""> 
"A       B        C       G       Xax
0.451   0.333   0.034   0.173   0.22        
0.491   0.270   0.033   0.207   0.34    
0.389   0.249   0.084   0.271   0.54    
0.425   0.819   0.077   0.281   0.34
0.457   0.429   0.053   0.386   0.53    
0.436   0.524   0.049   0.249   0.12    
0.423   0.270   0.093   0.279   0.61    
0.463   0.315   0.019   0.204   0.23
"
d <- span=""> read.delim(textConnection(s), sep="")

library(ggplot2)
library(reshape2)
d <- span=""> melt(d, id.vars="Xax")

# Everything on the same plot
ggplot(d, aes(Xax,value, col=variable)) + 
  geom_point() + 
  stat_smooth() 

Removing services from system boot

sudo update-rc.d -f postgresql remove
sudo update-rc.d -f mysql remove

or

In the Upstart system:
create a file called sudo vi /etc/init/nginx.override
and put the word "manual" in it.


sudo systemctl disable apache2  (Does not work for 14.04. It's for newer Ubuntu releases)

Stopping/starting nginx web server under Ubuntu 14.04

sudo service nginx start
sudo service nginx stop
sudo service nginx restart

More git commands

git remote show origin
* remote origin
  URL: git://github.com/rails/rails.git
  Remote branch merged with 'git pull' while on branch master
    master
  Tracked remote branches
    1-2-stable 2-0-stable 2-1-stable 2-2-stable 3-0-unstable master

$ git ls-remote --heads origin
5b3f7563ae1b4a7160fda7fe34240d40c5777dcd  refs/heads/1-2-stable
71926912a127da29530520d435c83c48778ac2b2  refs/heads/2-0-stable

$git log --decorate=full
$git log --decorate=full --pretty=oneline

#If I made a hard reset to a previous commit (but I had already pushed last commit), then I have to make a forced push:

$git reset --hard a9355ba42f5418c
$git push origin HEAD --force  #Erases in the online server the last commit