pixyj’s gists

pixyj / hero.js

Created November 28, 2013 06:48

Why you shouldn't miss new when invoking a constructor function in javascript

	//taken from Object Oriented Javascript by Stoyan Stefanov

	var Hero() {
	this.occupation = "Ninja!"
	this.say = function() {
	return "I'm a " + this.occupation;
	}
	}

	/* correct invocation of constructor function

pixyj / psycopg2_install_dependencies.sh

Last active December 28, 2015 08:09

Install these psycopg2 dependencies on Ubuntu before pip install psycopg2 to fix below error: In file included from psycopg/psycopgmodule.c:27:0: ./psycopg/psycopg.h:30:20: fatal error: Python.h: No such file or directory compilation terminated. error: command 'gcc' failed with exit status 1

	sudo apt-get install libpq-dev

	#I'm running postgresql-9.1. Match the version to that of your server.
	sudo apt-get install postgresql-server-dev-9.1
	sudo apt-get install python-dev

	#Now workon your virtualenv and pip install psycopg2

pixyj / iptables_firewall_rules

Created November 14, 2013 01:41

Sample iptables firewall settings from http://feross.org/how-to-setup-your-linode/

	*filter

	# Allow all loopback (lo0) traffic and drop all traffic to 127/8 that doesn't use lo0
	-A INPUT -i lo -j ACCEPT
	-A INPUT ! -i lo -d 127.0.0.0/8 -j REJECT

	# Accept all established inbound connections
	-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

	# Allow all outbound traffic - you can modify this to only allow certain traffic

pixyj / equi.go

Created September 15, 2013 06:21

Equivalent binary trees in Go Solution to http://tour.golang.org/#70

	// Copyright 2011 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	package main

	import (
	"fmt"
	"math/rand"
	)

pixyj / newtonraphson.go

Last active April 19, 2017 14:28

Solution to http://tour.golang.org/#24. Find the square root a number using Newton Raphson method

	package main

	import (
	"fmt"
	)

	func approx(z, x float64) float64 {
	z = z - (z*z - x)/2/z
	return z

pixyj / tour_35.go

Last active December 19, 2015 08:49

A tour of Go # 35 Straight line with slope == 1

	import "fmt";

	import "code.google.com/p/go-tour/pic"

	func Pic(dx, dy int) [][]uint8 {
	phew := make([][]uint8, dx)

	for i := range phew {
	phew[i] = make([]uint8, dy)
	for j := range phew[i] {

pixyj / count_dom_nodes.js

Created June 14, 2013 09:15

Calculate total number of nodes in your web page.

	var countNodes = function() {
	var total = 1;
	var count = function(node) {
	var i, l;
	l = node.children.length;
	total += l;
	for(i=0; i<l; i++) {
	count(node.children[i])
	}
	}

pixyj / Makefile

Last active February 10, 2023 09:48

Simple HTTP client in C

	all:
	gcc -Wall http_client.c -o http_client

	clean:
	rm *.o;rm http_client

pixyj / validate_properties.js

Last active December 14, 2015 23:49

Check if a javascript object(instance) has the same properties of the same type with respect to a known object(schema).

	/*******************************************************************************************************
	Checks if an object(instance) has the same properties of the same type with respect to a known
	object(schema).

	validate is especially useful to test whether the server side code sends JSON as expected by the client


	Usage Example:
	1. Create a sample expected object (sampleSchema).
	2. When data(sampleInstance) is received, call validate(sampleSchema, sampleInstance)

pixyj / count_change.py

Last active December 11, 2015 04:58

	def ways(amount, coin_types):

	"""
	Python implementation for the counting_change problem
	http://mitpress.mit.edu/sicp/full-text/book/book-Z-H-11.html#%_sec_1.2

	Doesn't work for large numbers because we don't have tail call optimization in python

	Time complexity analysis: Found an explanation at
	http://wqzhang.wordpress.com/2009/06/09/sicp-exercise-1-14/

Pramod Lakshmanan pixyj