izmailoff’s gists

izmailoff / FindReadPositionInGenome.scala

Created February 13, 2016 03:32

Solution for https://courses.edx.org/courses/course-v1:ColumbiaX+DS102X+1T2016 - You are given the following five 14-long reads below. Map them to the sequence of the gene responsible for the ABO blood type , keeping in mind that each read might include a single nucleotide error. Report their respective starting positions along the gene (answers…

	// not optimized, just a quick way to code it up...

	// data from: http://www.ncbi.nlm.nih.gov/nuccore/LC068776.1

	val s1 = "ccggcctcgggaag"

	val s2 = "ttgcggacgctagc"

	val s3 = "tcgggctccccccg"

izmailoff / DAGFuture.scala

Created April 3, 2016 13:34

	import scala.concurrent.{Await, Future}
	import scala.concurrent.ExecutionContext.Implicits.global
	import scala.concurrent.duration._
	import scala.util.Try

	case class Node[T](value: T, children: List[Node[T]])

	object DagFuture extends App {

	def run[A, B](node: Node[A], result: B)(nodeEval: (Node[A], B) => B)(aggregator: Traversable[B] => B): Future[B] = {

izmailoff / Perms.scala

Created April 14, 2016 03:34

Implementation of permutations in Scala (functional, recursive, lazy)

	object Perms extends App {

	def perms[T](xs: List[T]): Stream[List[T]] =
	xs match {
	case Nil => Stream.empty
	case single@List(e) => Stream(single)
	case l =>
	val s = for {
	i <- (0 until l.length).toStream
	(pref, suf) = l.splitAt(i)

izmailoff / deeplearning4j.properties

Created April 18, 2016 09:27

Set these JVM args with -D flag to avoid using native BLAS library and use Java impl instead for deeplearning4j.

	-Dcom.github.fommil.netlib.BLAS=com.github.fommil.netlib.F2jBLAS
	-Dcom.github.fommil.netlib.LAPACK=com.github.fommil.netlib.F2jLAPACK
	-Dcom.github.fommil.netlib.ARPACK=com.github.fommil.netlib.F2jARPACK

izmailoff / profile_system.py

Created June 25, 2016 07:54

Cross-platform Python script for collecting CPU and memory usage

	# Prints % of total CPU and memory used in the system

	# Requires psutil. Install with:
	# `pip install psutil`
	# or something like:
	# `dnf install python3-psutil`

	# Run with:
	# `python3 profile_system.py`
	# Ctrl + C to exit

izmailoff / New_Right_Biased_Either_example.scala

Last active February 13, 2018 09:35

Illustrates the use of the new implementation of Either that supports map, flatMap, etc. It's available since 2.12.0-RC1.

	case class Error(message: String)
	case class User(id: Int, name: String, accountId: Int)
	case class Account(id: Int, balance: Double)
	case class Item(id: Int, title: String, price: Double)
	case class Failures(isUserFailure: Boolean, isAccountFailure: Boolean, isItemFailure: Boolean)

	def getUser(id: Int, fail: Boolean = false): Either[Error, User] =
	if(fail) Left(Error(s"No such user: $id")) else Right(User(id, "Bob", 3))

	def getAccount(id: Int, fail: Boolean = false): Either[Error, Account] =

izmailoff / string_list_parser.scala

Created September 26, 2016 03:05

Just an example of matching arbitrary length of list with a list of matchers (PF)

	val `namespace` = "namespace"
	val `elementTerminator` = "elementTerminator"
	val `openBracket` = "openBracket"
	val `closeBracket` = "closeBracket"

	// list of partial functions from list of strings to string:
	val patterns = List[PartialFunction[List[String], String]](
	{ case `namespace` :: value :: `elementTerminator` :: rest => "case1" },
	{ case `openBracket` :: rest => "case2" },
	{ case `closeBracket` :: `elementTerminator` :: rest => "case3" })

izmailoff / Function_composition_in_scala_example.scala

Created September 29, 2016 05:59

One of the ways to compose functions



	val add1 = (x: Int) => x + 1

	val add100 = (x: Int) => x + 100

	val square = (x: Int) => x * x

	val allFunctions = List(add1, add100, square)

izmailoff / functional_take_first_n_elements_list.scala

Created September 29, 2016 08:25

Take first n elements from scala list example - functional


	def take[A](xs: List[A], n: Int): List[A] = {
	def loop(xy: List[A], rem: Int, accu: List[A]): List[A] =
	if(rem <= 0) accu
	else xy match {
	case h :: t => loop(t, rem - 1, accu ::: List(h))
	case _ => accu
	}
	loop(xs, n, Nil)
	}

izmailoff / function_set_scala_example.scala

Last active December 15, 2017 03:44

Example of functional sets in Scala


	type Set = Int => Boolean

	val setOf_1: Set = (i: Int) => (i == 1)

	val empty: Set = (i: Int) => false

	val union: (Set, Set) => Set =
	(s1: Set, s2: Set) => (i: Int) => s1(i) \|\| s2(i)

Aleksey Izmailov izmailoff