AlexanderSavochkin’s gists

AlexanderSavochkin / essentials-mlr.h

Last active November 30, 2015 05:04

Multinomial logistic regression model header file

	class MultinomialLogRelModel
	{
	//Основные параметры модели
	int num_classes; //Количество классов
	int num_sample_features; //Количество признаков в объектах
	valarray<double> model_weights; //Веса модели
	double regularization_coeff; //Коэффициент регуляризации
	double learning_rate; //Параметр шага в методе градиентного спуска
	public:
	...

AlexanderSavochkin / mlt_gradient_for_sample.cpp

Created December 3, 2015 07:26

Piece of code for calculation of likehood gradient in multinomial logistic regression for one training sample

	void MultinomialLogRelModel::gradientForSample(const valarray<double>& sample_features, int label, valarray<double>& gradient) const
	{
	double sum_exp = 0.0;
	valarray<double> features(0.0, (num_sample_features + 1) * num_classes);
	valarray<double> gradient_add(0.0, (num_sample_features + 1) * num_classes);

	for (int k = 0; k < num_classes; ++k)
	{
	featurize(sample_features, k, features);
	double wf = inner_product(begin(model_weights), end(model_weights), begin(features), 0.0);

AlexanderSavochkin / LogisticRegression.scala

Created December 9, 2015 07:19

	//Logistic regression example from Saprk documentation
	val points = spark.textFile(...).map(parsePoint).cache()
	var w = Vector.random(D) // current separating plane
	for (i <- 1 to ITERATIONS) {
	val gradient = points.map(p =>
	(1 / (1 + exp(-p.y(w dot p.x))) - 1) p.y * p.x
	).reduce(_ + _)
	w -= gradient
	}
	println("Final separating plane: " + w)

AlexanderSavochkin / mlr_featurize.cpp

Created December 10, 2015 05:35

	void MultinomialLogRelModel::featurize(const valarray<double>& sample_features, int label, valarray<double>& modelFeatures) const
	{
	for (int k = 0; k < num_classes; ++k) //Loop through classes
	{
	for (int i = 0; i < num_sample_features; ++i ) //loop through features
	{
	modelFeatures[k * (num_sample_features + 1) + i] = (k == label ? sample_features[i] : 0.0);
	}
	modelFeatures[(k + 1) * (num_sample_features + 1) - 1] = (k == label ? 1.0 : 0.0);
	}

AlexanderSavochkin / blink-lpc1114.s

Last active March 25, 2016 17:16

Simple LED blink program for LPC1114 in assembly

	.syntax unified

	/Инструктируем транслятор генерировать 16-битные инструкции Thumb/
	.thumb

	/*То же самое что ключ командной строки -mcpu=cortex-m0 .
	Говорим транслятору, что хотим код под архитектуру Cortex-M0*/
	.cpu cortex-m0

	/* Опрделяем секцию .vectors, в которой описываем таблицу прерываний */

AlexanderSavochkin / blink-lpc1114.ld

Last active March 25, 2016 07:49

LPC1114 minimalistic linker script

	/* useful reference: www.linuxselfhelp.com/gnu/ld/html_chapter/ld_toc.html */
	MEMORY
	{
	flash : org = 0x00000000, len = 32k
	}

	SECTIONS
	{

	. = ORIGIN(flash);

AlexanderSavochkin / uber-install-213.sh

Created April 12, 2016 03:23 — forked from dannguyen/uber-install-213.sh

Make everything install on Ubuntu 14.04 and 14.10, specifically for AWS and DigitalOcean

	## Tested on 14.04 and 14.10. Runs as root because why not
	## Installs:
	# - Ubuntu developer tools
	# - Python (using system 2.7.6 / 2.7.8)
	# - scipy libs
	# - scikit-learn
	# - nltk
	# - Ruby 2.1.5
	# - rbenv
	# - nokogiri

AlexanderSavochkin / blink-lpc1114.c

Last active April 21, 2016 16:29

LED blink with LPC1114 in C

	#define REGISTER_32(ADDRESS) (((volatile unsigned int )(ADDRESS)))
	#define SYSAHBCLKCTRL REGISTER_32(0x40048080)
	#define GPIO0DATA REGISTER_32(0x50003ffc)
	#define GPIO0DIR REGISTER_32(0x50008000)

	int main()
	{
	// Turn on clock for GPIO and IOCON
	SYSAHBCLKCTRL \|= (1 << 6) + (1 << 16);
	GPIO0DIR = (1 << 7); // Make PIO0_7 an output

AlexanderSavochkin / startup-lpc1114.s

Last active April 15, 2016 04:40

LPC1114 startup code in assembly

	.syntax unified

	/Инструктируем транслятор генерировать 16-битные инструкции Thumb/
	.thumb

	/*То же самое что ключ командной строки -mcpu=cortex-m0 .
	Говорим транслятору, что хотим код под архитектуру Cortex-M0*/
	.cpu cortex-m0

	/* Опрделяем секцию .vectors, в которой описываем таблицу прерываний */

AlexanderSavochkin / startup-lpc1114.c

Created April 15, 2016 18:39

Startup code for lpc1114 MCU in C

	void Default_Handler(void);
	void init();

	const void * Vectors[] __attribute__((section(".vectors"))) ={
	(void )0x10002000, / Top of stack */
	init, /* Reset Handler */
	Default_Handler, /* NMI */
	Default_Handler, /* Hard Fault */
	0, /* Reserved */
	0, /* Reserved */

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