hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

zflat

# Export the Heroku PG database to a local dump file
# https://devcenter.heroku.com/articles/heroku-postgres-import-export#export
heroku pgbackups:capture
curl -o latest.dump `heroku pgbackups:url`

# Install postregs & Setup  password
# https://help.ubuntu.com/community/PostgreSQL

# List databases
sudo -u postgres psql -l

baali

from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.metrics.pairwise import linear_kernel
import numpy as np
from itertools import combinations
from random import shuffle

def majorclust_sklearn():    
    texts = [
        "foo blub baz",
        "foo bar baz",

lelandbatey

Description

This simple script will take a picture of a whiteboard and use parts of the ImageMagick library with sane defaults to clean it up tremendously.

The script is here:

#!/bin/bash
convert "$1" -morphology Convolve DoG:15,100,0 -negate -normalize -blur 0x1 -channel RBG -level 60%,91%,0.1 "$2"

Results

edrex

Let's set up Camlistore on a Linux server, with blobs stored in s3. This seems to be the currently best-supported option for "cloud" deployment.

This is meant as a supplement to the official server config doc. Read through both docs before you start.

http://camlistore.org/docs/server-config

This blog post is also recommended reading.

I've posted my config files for reference, but they will be created the first time you run camlistored (for the server) and camput init (for the client) so don't copy them.

fperez

alysonla

-- Active issues
-- Count of total active issues in the specified time frame
-- Source: githubarchive public data set via Google BigQuery http://githubarchive.org/

SELECT
	COUNT(DISTINCT JSON_EXTRACT_SCALAR(events.payload, '$.issue.id')) AS events_issue_count
FROM (SELECT * FROM TABLE_DATE_RANGE([githubarchive:day.],TIMESTAMP('2015-09-01'),TIMESTAMP('2016-08-31')))
 AS events

-- 10,723,492 active issues

brianhuey

from ortools.constraint_solver import pywrapcp
# Python Implementation of
# https://github.com/google/or-tools/blob/master/examples/cpp/sports_scheduling.cc
# By Brian Huey
# Sports scheduling problem.
#
# We want to solve the problem of scheduling of team matches in a
# double round robin tournament.  Given a number of teams, we want
# each team to encounter all other teams, twice, once at home, and
# once away. Furthermore, you cannot meet the same team twice in the

bep

First install Termux

Then there are two options:

Build from source

Open the Termux terminal on your Android device and copy-and-paste the commands listed below and hit ENTER:

steven2358

FFmpeg cheat sheet

A list of useful commands for the FFmpeg command line tool.

Download FFmpeg: https://www.ffmpeg.org/download.html

Full documentation: https://www.ffmpeg.org/ffmpeg.html

Basic conversion