wkschwartz’s gists

wkschwartz / spreads-example.do

Last active August 29, 2015 14:01

Example of spreads data & code in Stata

	spreads_read using spreads.csv, clear
	collapse (firstnm) open_pinnacle=pinnacle_spread ///
	open_betonline=betonline_spread ///
	open_bookmaker=bookmaker_spread ///
	points_* ///
	(lastnm) close_pinnacle=pinnacle_spread ///
	close_betonline=betonline_spread ///
	close_bookmaker=bookmaker_spread, ///
	by(season week hometeam awayteam game_date)
	generate byte actual = points_home - points_away

wkschwartz / keybase.md

Created April 5, 2014 21:29

Keybase proof

I hereby claim:

I am wkschwartz on github.
I am wkschwartz (https://keybase.io/wkschwartz) on keybase.
I have a public key whose fingerprint is BD4C C2D4 F957 4C11 8383 A479 F609 7642 2AA9 4204

To claim this, I am signing this object:

wkschwartz / dfs.go

Created September 16, 2013 14:50

An example of using Ruby-block-like callbacks for iteration in Go. This example is basic depth-first search on an undirected graph. The function using the "block" is `dfs`, at the end.

	// Undirected graph where each node is labeled by a small integer.
	type Graph struct {
	neighbors [][]int // a list of neighbors for each node
	}

	// Omitting code to initialize a graph. The initializer would take the number
	// of nodes and set up the neighbors array to be the right length. Another method
	// would be available to add a neighbor to a given vertex. That way for a
	// Graph `g`, `g.neighbors[node]` would be an array of nodes adjacent to `node`.

wkschwartz / profiling.py

Created April 24, 2013 21:55

Timing/profiling tests on different branches of https://github.com/wkschwartz/algorithms2

	from math import sqrt

	def ttest(x1, x2):
	"Student's t-test for unpaired, equal variance, equal size samples."
	if len(x1) != len(x2):
	raise ValueError('unequal sample sizes')
	mx1 = sum(x1) / len(x1)
	mx2 = sum(x2) / len(x2)
	s2x1 = sum((xi - mx1)**2 for xi in x1) / (len(x1) - 1)
	s2x2 = sum((xi - mx2)**2 for xi in x2) / (len(x2) - 1)

wkschwartz / sort.c

Last active December 16, 2015 09:08

Experiments with an LSD Radix sort

	#include <stdlib.h> /* malloc, free */
	#include <stdio.h> /* NULL */

	/**
	* Stably sort and array of unsigned integers in place in linear time. Uses
	* linear extra space. Return 0 on failure to allocate memory and 1 on success.
	*
	* Author: William Schwartz
	*/
	int sort(unsigned int a[], size_t len) {

wkschwartz / gist:5295571

Last active December 15, 2015 17:19

Java utility method for helping me find outliers for the Princeton/Coursera Algorithms Part 2 course assignment "WordNet."

	/**
	* Reflect a upper triangular matrix across its diagonal and return the row
	* index whose sum is greatest, without modifying the input matrix.
	* <p>
	* The non-mutating reflection is accomplished by adding down column <em>i</em>
	* from 0 to <em>i</em> - 1 and adding across row <em>i</em> from <em>i</em> to
	* <code>a[i].length</code>.
	*
	* @param a An array of arrays of integers in row-major form. The arrays should
	* but do not have to be equal lengths.

wkschwartz / new_bashrc.sh

Created August 11, 2012 16:08 — forked from josephwecker/new_bashrc.sh

Replace .bashrc, .bash_profile, .profile, etc. with something much more clean, consistent, and meaningful.

	#!/bin/bash
	# License: Public Domain.
	# Author: Joseph Wecker, 2012
	#
	# Are you tired of trying to remember what .bashrc does vs .bash_profile vs .profile?
	# Are you tired of trying to remember how darwin/mac-osx treat them differently from linux?
	# Are you tired of not having your ~/.bash* stuff work the way you expect?
	#
	# Symlink all of the following to this file:
	# * ~/.bashrc

William Schwartz wkschwartz

Keybase proof