Skip to content

Instantly share code, notes, and snippets.

@jboner
jboner / latency.txt
Last active August 20, 2025 21:38
Latency Numbers Every Programmer Should Know
Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference 0.5 ns
Branch mispredict 5 ns
L2 cache reference 7 ns 14x L1 cache
Mutex lock/unlock 25 ns
Main memory reference 100 ns 20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy 3,000 ns 3 us
Send 1K bytes over 1 Gbps network 10,000 ns 10 us
Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD
@Nurdok
Nurdok / python_conversion.md
Last active June 18, 2025 08:46
Python Conversion

Python Number Conversion Chart

From To Expression
@jsundram
jsundram / heatmat.py
Created January 18, 2013 19:52
Heatmap in python like this one on flowingdata, see stackoverflow for context: http://stackoverflow.com/questions/14391959/heatmap-in-matplotlib-with-pcolor
import matplotlib.pyplot as plt
import numpy as np
column_labels = list('ABCD')
row_labels = list('WXYZ')
data = np.random.rand(4,4)
fig, ax = plt.subplots()
heatmap = ax.pcolor(data, cmap=plt.cm.Blues)
# put the major ticks at the middle of each cell
ax.set_xticks(np.arange(data.shape[0])+0.5, minor=False)
@dypsilon
dypsilon / frontendDevlopmentBookmarks.md
Last active July 12, 2025 14:05
A badass list of frontend development resources I collected over time.
@ragingwind
ragingwind / Backend Architectures Keywords and References.md
Last active July 22, 2025 10:47
Backend Architectures Keywords and References
@lrhache
lrhache / python-selenium-open-tab.md
Last active June 16, 2025 14:45
Python Selenium - Open new tab / focus tab / close tab

On a recent project, I ran into an issue with Python Selenium webdriver. There's no easy way to open a new tab, grab whatever you need and return to original window opener.

Here's a couple people who ran into the same complication:

So, after many minutes (read about an hour) of searching, I decided to do find a quick solution to this problem.

@debasishg
debasishg / gist:8172796
Last active June 23, 2025 05:56
A collection of links for streaming algorithms and data structures

General Background and Overview

  1. Probabilistic Data Structures for Web Analytics and Data Mining : A great overview of the space of probabilistic data structures and how they are used in approximation algorithm implementation.
  2. Models and Issues in Data Stream Systems
  3. Philippe Flajolet’s contribution to streaming algorithms : A presentation by Jérémie Lumbroso that visits some of the hostorical perspectives and how it all began with Flajolet
  4. Approximate Frequency Counts over Data Streams by Gurmeet Singh Manku & Rajeev Motwani : One of the early papers on the subject.
  5. [Methods for Finding Frequent Items in Data Streams](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.187.9800&rep=rep1&t
@osipov
osipov / Makefile
Last active August 29, 2015 14:04
Makefile to download and build Spark 1.0.1 against Hadoop 2.4.0 on Ubuntu 14.04
all: prereq build
prereq:
apt-get -y install git
apt-get -y install curl
apt-get -y install openjdk-7-jdk
apt-get -y install maven
git clone https://github.com/apache/spark.git
cd spark; git checkout tags/v1.0.1
build:
export SPARK_HADOOP_VERSION=2.4.0
// XPath CheatSheet
// To test XPath in your Chrome Debugger: $x('/html/body')
// http://www.jittuu.com/2012/2/14/Testing-XPath-In-Chrome/
// 0. XPath Examples.
// More: http://xpath.alephzarro.com/content/cheatsheet.html
'//hr[@class="edge" and position()=1]' // every first hr of 'edge' class
@debasishg
debasishg / gist:b4df1648d3f1776abdff
Last active June 20, 2025 13:59
another attempt to organize my ML readings ..
  1. Feature Learning
  1. Deep Learning