cpursley

PostgreSQL is Enough

• Simplify: move code into database functions
• Just Use Postgres for Everything
• Just use Postgres
• PostgreSQL is the worlds’ best database
• Postgres is eating the database world
• Hacker News discussion

Background and Cron Jobs

Victornovikov

Calculus

Matrix derivatives

• A good collection of links on matrix derivatives https://gist.github.com/yig/c1959ce997f1d2fd6f3f982cb482e060

• A gentle intro. This series gives an overview of gradient, Jacobian and importance of chain rule for NN

  • https://www.lesswrong.com/posts/9L9XuXhLYBm47yYkf/a-primer-on-matrix-calculus-part-1-basic-review

• https://www.lesswrong.com/s/nMGrhBYXWjPhZoyNL/p/KKwv9kcQz29vqPLAD

yig

Matrix derivatives via Frobenius norm

# Automatic matrix derivatives: http://www.matrixcalculus.org/

# A good primer on basic matrix calculus: https://atmos.washington.edu/~dennis/MatrixCalculus.pdf
# The Matrix Reference Manual: http://www.ee.ic.ac.uk/hp/staff/dmb/matrix/intro.html#Intro
# Trying to understand the derivative of the inverse: https://math.stackexchange.com/questions/1471825/derivative-of-the-inverse-of-a-matrix
# Derivative of the pseudoinverse:
    https://math.stackexchange.com/questions/2179160/derivative-of-pseudoinverse-with-respect-to-original-matrix
    https://mathoverflow.net/questions/25778/analytical-formula-for-numerical-derivative-of-the-matrix-pseudo-inverse

yi-jiayu

import time

from telethon import TelegramClient, events

# sample API_ID from https://github.com/telegramdesktop/tdesktop/blob/f98fdeab3fb2ba6f55daf8481595f879729d1b84/Telegram/SourceFiles/config.h#L220
# or use your own
api_id = 17349
api_hash = '344583e45741c457fe1862106095a5eb'

# fill in your own details here

daviderestivo

(defun drestivo/org-download-method (link)
  "This is an helper function for org-download.
It creates an \"./image\" folder within the same directory of the org file.
Images are separated inside that image folder by additional folders one per
org file.
More info can be found here: https://github.com/abo-abo/org-download/issues/40.
See the commit message for an example:
https://github.com/abo-abo/org-download/commit/137c3d2aa083283a3fc853f9ecbbc03039bf397b"
  (let ((filename
         (file-name-nondirectory

timvieira

"""
Simple example of manually performing "automatic" differentiation
"""
import numpy as np
from numpy import exp, sin, cos


def f(x, with_grad=False):
    # Need to cache intermediates from forward pass (might not use all of them).
    a = exp(x)

adham90

SPC s c remove highlight

**** Files manipulations key bindings
Files manipulation commands (start with ~f~):

| Key Binding | Description                                                    |
|-------------+----------------------------------------------------------------|
| ~SPC f c~   | copy current file to a different location                      |
| ~SPC f C d~ | convert file from unix to dos encoding                         |
| ~SPC f C u~ | convert file from dos to unix encoding                         |

vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

crittelmeyer

Vim Cheatsheet

As configured in my dotfiles

Intro Resources

• Your problem with Vim is that you don't grok vi (on StackOverflow)
• Coming Home to Vim
• VimCasts.org
• Vim Galore
• Vim Adventures!

brijeshb42

import os
import json
import datetime

from flask import Flask, url_for, redirect, \
    render_template, session, request
from flask.ext.sqlalchemy import SQLAlchemy
from flask.ext.login import LoginManager, login_required, login_user, \
    logout_user, current_user, UserMixin
from requests_oauthlib import OAuth2Session