Agatha agathauy

If your running a x64 bit Ubuntu or other Linux and find USB transfers hang at the end apply this fix:

echo $((16*1024*1024)) > /proc/sys/vm/dirty_background_bytes
echo $((48*1024*1024)) > /proc/sys/vm/dirty_bytes

I suggest you edit your /etc/rc.local file to make this change persistant across reboots.

sudo nano /etc/rc.local

Module autoreload

To auto-reload modules in jupyter notebook (so that changes in files *.py doesn't require manual reloading):

# for auto-reloading external modules
# see http://stackoverflow.com/questions/1907993/autoreload-of-modules-in-ipython
%load_ext autoreload
%autoreload 2

Cross platform interface for virtualenv

Unless you use some Windows specific libraries; or an alternate Python implementation (like IronPython), there is nothing to worry about.

Many people (including myself) use Windows for development and deploy on Linux for production and use virtualenv for this purpose. It is designed to make your environment portable.

You don't push the entire virtualenv to Linux.

Once you have your virtual environment ready and your code is working, you should freeze the requirements for your application:

exFAT support on macOS seems to have some bugs because my external drives with exFAT formatting will randomly get corrupted.

If Disk Utility is unable to repair, consider trying this:

In Disk Utility, ensure that the drive is not mounted, eject it if it is mounted.
Use diskutil list to find the right drive id.
You want the id under the IDENTIFIER column, it should look like disk1s1
Run sudo fsck_exfat -d <id from above>. eg sudo fsck_exfat -d disk1s3
-d is debug so you'll see all your files output as they're processed.

psql: FATAL: Peer authentication failed for user “postgres” (or any user)

The connection failed because by default psql connects over UNIX sockets using peer authentication, that requires the current UNIX user to have the same user name as psql. So you will have to create the UNIX user postgres and then login as postgres or use sudo -u postgres psql database-name for accessing the database (and psql should not ask for a password).

If you cannot or do not want to create the UNIX user, like if you just want to connect to your database for ad hoc queries, forcing a socket connection using psql --host=localhost --dbname=database-name --username=postgres (as pointed out by @meyerson answer) will solve your immediate problem.

But if you intend to force password authentication over Unix sockets instead of the peer method, try changing the following pg_hba.conf* line:

from

The repository for the assignment is public and Github does not allow the creation of private forks for public repositories.

The correct way of creating a private frok by duplicating the repo is documented here.

For this assignment the commands are:

Create a bare clone of the repository. (This is temporary and will be removed so just do it wherever.)

git clone --bare git@github.com:usi-systems/easytrace.git

Using DiffMerge as your git mergetool (for Mac OS X / macOS)

Reference(s):

Step 1: download and install the DiffMerge OS X Installer

http://www.sourcegear.com/diffmerge/downloads.php - get the installer version, NOT the dmg version

	sudo add-apt-repository "deb http://apt.postgresql.org/pub/repos/apt/ xenial-pgdg main"
	wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc \| sudo apt-key add -
	sudo apt-get update
	sudo apt-get install postgresql-9.6

	sudo apt-get install postgresql-9.6-postgis-2.3
	sudo apt-get install postgresql-9.6-pgrouting

	sudo add-apt-repository ppa:ubuntugis/ubuntugis-unstable
	sudo apt-get update

	import React from 'react'
	import axios, { post } from 'axios';

	class SimpleReactFileUpload extends React.Component {

	constructor(props) {
	super(props);
	this.state ={
	file:null
	}