YKCzoli

Processing LiDAR to extract building heights

Walk through

Detailed walk through of building extraction using postgis

First lets pull a data layer from of openstreetmap. You can do this any which way you’d like, as there are a variety of methods for pulling openstreetmap data from their database. Check the [wiki] (http://wiki.openstreetmap.org/wiki/Downloading_data) for a comprehensive list. My favourite method thus far is pulling the data straight into QGIS using the open layers plugin. For those who may want to explore this method, check [this tutorial] (http://www.qgistutorials.com/en/docs/downloading_osm_data.html). For building extraction you only need building footprints, and include the building tags. Not all polygons are of type building in OSM, so we can download all the polygons, and then filter the layer for only polygons tagged as buildings.

LiDAR data was pulled from USGS via the Earth Explorer site. [Here] (http://earthobservatory.nasa.gov/blogs/ele

nyxcalamity

#!/bin/bash
#Cleans up glassfish domain folders so that the maven deployment with cargo doesn't hang.
#---------------------------------------------------------------------------------------------------
# CUSTOMIZATION SECTION START
#---------------------------------------------------------------------------------------------------
export GF_DIR=/home/nyxcalamity/ws/appservers/glassfish
#---------------------------------------------------------------------------------------------------
# CUSTOMIZATION SECTION END
#---------------------------------------------------------------------------------------------------
export OK="$(tput setaf 2) DONE$(tput sgr0)"

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

jahewson

# Licensed under CC BY 3.0 http://creativecommons.org/licenses/by/3.0/
# Derived works must attribute https://gist.github.com/4492300 at the beginning, and the date.

##################################################################
Installing and Configuring SmartOS on a budget server (with a /29)
##################################################################

# if you find this gist useful, please star it

# please be aware that budget hosting companies usually cut corners somewhere,

mtigas

[mike.tig.as][mta] server configuration

This gist contains the nginx and tor configurations for the [mike.tig.as][mta] servers, mainly to show:

• Use of the chris-lea/nginx-devel PPA to allow use of SPDY.
• ssl_ciphers selection to mitigate BEAST attack, enable [perfect forward secrecy][pfs] if possible and select the strongest possible ciphers within those bounds. (Exception is made for several ciphers at the end of list, for compatibility reasons.)

dallasmarlow

# convert the last 4 octets of a mac address to base 10 for a numeric value between 0-4294967295 (which is the supported range for mysql's server-id)
# example mac address - "00:26:9E:2B:C7:36"

mac_address.split(':')[2..5].join.to_i(16)

# => 2653669174

paulirish

Open Conference Expectations

This document lays out some baseline expectations between conference speakers and conference presenters. The general goal is to maximize the value the conference provides to its attendees and community and to let speakers know what they might reasonably expect from a conference.

We believe that all speakers should reasonably expect these things, not just speakers who are known to draw large crowds, because no one is a rockstar but more people should have the chance to be one. We believe that conferences are better -- and, dare we say, more diverse -- when the people speaking are not just the people who can afford to get themselves there, either because their company paid or they foot the bill themselves. Basically, this isn't a rock show rider, it's some ideas that should help get the voices of lesser known folks heard.

These expectations should serve as a starting point for discussion between speaker and organizer. They are not a list of demands; they are a list of rea

jboner

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

dcernst

% --------------------------------------------------------------
% This is all preamble stuff that you don't have to worry about.
% Head down to where it says "Start here"
% --------------------------------------------------------------
 
\documentclass[12pt]{article}
 
\usepackage[margin=1in]{geometry} 
\usepackage{amsmath,amsthm,amssymb}
 

wilsonpage

// module dependencies
var http = require('http'),
    url = require('url');


 /**
  * UrlReq - Wraps the http.request function making it nice for unit testing APIs.
  * 
  * @param  {string}   reqUrl   The required url in any form
  * @param  {object}   options  An options object (this is optional)