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

erikreagan

Mac web developer apps

This gist's comment stream is a collection of webdev apps for OS X. Feel free to add links to apps you like, just make sure you add some context to what it does — either from the creator's website or your own thoughts.

— Erik

ChickenProp

I turned my Raspberry Pi into a robot, controlled by a Wii nunchuk. It's surprisingly easy to do - at least, surprisingly to me, who has not previously made a robot. But because it's surprising, it might help others to have a guide, so here one is.

Parts

I'm linking to SKPang for most of these, but Sparkfun and Adafruit would be good places to look if you're in the US.

(If you're in the UK, a word of caution - I bought motors and some other stuff from Sparkfun to save £7 over SKPang, but the package got stopped at customs and I had to pay £4 VAT and £8 handling fees. My understanding is that this will only happen on packages whose contents are worth more than £15, but you'd be a fool to trust me on this. It didn't happen when I spent £20 at Adafruit or £5 at Sparkfun. YMMV.)

• Raspberry Pi - for the robot logic. An Arduino or similar could be substituted (though the software would need to be rewritten).

sarg

Obtaining RK3066 boot ROM.

Here are my steps.

At first, I took a look to RK30xxLoader(L)_V1.18.bin. This file appears in update.img for my device. So, I unpacked update.img using rk29Kitchen.

strings on that file returns nothing interesting, so I assumed the file is crypted

phuesler

diff --git a/Makefile b/Makefile
index d8009c7..a74a6ee 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@
 
 CC=g++
 DEFINES = -DUNITY_MASTERSERVER
-CFLAGS=-Wall -lpthread $(DEFINES)
+CFLAGS=-Wall -pthread $(DEFINES)

bradmontgomery

Setting up a SSL Cert from Comodo

I use Namecheap.com as a registrar, and they resale SSL Certs from a number of other companies, including Comodo.

These are the steps I went through to set up an SSL cert.

Purchase the cert

wsargent

303 See Other

Location: https://github.com/wsargent/docker-cheat-sheet

Hi there!

The docker cheat sheet has moved to a Github project under https://github.com/wsargent/docker-cheat-sheet.

Please click on the link above to go to the cheat sheet.

bsweger

Useful Pandas Snippets

A personal diary of DataFrame munging over the years.

Data Types and Conversion

Convert Series datatype to numeric (will error if column has non-numeric values)
(h/t @makmanalp)

KdotJPG

/**
 * K.jpg's OpenSimplex 2, smooth variant ("SuperSimplex")
 *
 * More language ports, as well as legacy 2014 OpenSimplex, can be found here:
 * https://github.com/KdotJPG/OpenSimplex2
 */

public class OpenSimplex2S {

    private static final long PRIME_X = 0x5205402B9270C86FL;

Mistobaan

These instructions will explain how to install tensorflow on mac with cuda enabled GPU suport. I assume you know what tensorflow is and why you would want to have a deep learning framework running on your computer.

Prerequisites

Make sure to update your homebrew formulas

brew update