Install R-base 3.1.1 on Ubuntu 14.04

sudo add-apt-repository ppa:marutter/rrutter

sudo apt-get update

sudo apt-get upgrade

sudo apt-get install r-base r-base-dev

set static ip ubuntu

1. Set IP changes in "/etc/network/interfaces"

auto eth0
iface eth0 inet static

address 136.187.xx.xx
netmask 255.255.248.0
gateway 136.187.80.1

2. Don't give your DNS configurations in /etc/resolv.conf because while we restart the server sometimes the configuration get erased.
 So use vim /etc/resolvconf/resolv.conf.d/base (while updating configs in this it doesn't get removed).

search  (domain name)
nameserver 8.8.8.8
nameserver 8.8.4.4

How to create a bootable USB stick on OS X

From Ask Ubuntu

isntall R and other packages

install.packages('ggplot2', dependencies=T)

using above can install ggplot2 package. 

install ndnsim on mac

virtualenv --python=python3.5 .venv
source .venv/bin/activate

Flask, how to send email. Configuration

   Using gmail as flask's sendmail server

1, First configure flask as below:     

        MAIL_SERVER = 'smtp.gmail.com'
MAIL_PORT = 587
MAIL_USERNAME = 'email@gmail.com'
MAIL_PASSWORD = 'password'
MAIL_USE_TLS = True
MAIL_USE_SSL = False

2, Change your google account settings: 

Google blocks sign-in attempts from apps which do not use modern security standards(mentioned on their support page). You can however, turn on/off this safety feature by going into the link below:

Go to this link and select turn on :

https://www.google.com/settings/security/lesssecureapps

file size

1. individual file size : ls -lh file
2. free and used place on the disk : df  -h
3. total folder size : du -hs