Mark Lewis MarkCLewis
MarkCLewis
/ NBodyImmutableClass.scala
Last active
January 3, 2017 19:07
This code uses immutable body and 3-D vector classes with a mutable array to do a basic N-body simulation.
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| case class Vect3(x: Double, y: Double, z: Double) { | |
| def +(v: Vect3) = Vect3(x+v.x, y+v.y, z+v.z) | |
| def -(v: Vect3) = Vect3(x-v.x, y-v.y, z-v.z) | |
| def *(c: Double) = Vect3(x*c, y*c, z*c) | |
| def /(c: Double) = Vect3(x/c, y/c, z/c) | |
| } | |
| case class ImmutableBody(p: Vect3, v: Vect3, mass: Double) { | |
| def step(a: Vect3, dt: Double) = { | |
| val nv = v+a*dt |
MarkCLewis
/ NBodyMutableClass.scala
Created
January 3, 2017 16:51
This code does a basic N-body simulation using arrays of mutable classes. This approach mirrors what is done in languages like C++, but the memory model is different so the array actually holds references to the bodies and the bodies could be distributed through memory.
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| class MVect3(var x: Double, var y: Double, var z: Double) { | |
| def zero(): Unit = { | |
| x = 0.0 | |
| y = 0.0 | |
| z = 0.0 | |
| } | |
| } | |
| class MutableBody( | |
| val p: MVect3, |
MarkCLewis
/ NBodyArray.scala
Created
January 1, 2017 21:05
This is a little code segment that I wrote to do a time comparison of the speed of Scala for and while loops between 2.11 and 2.12. This code uses a lot of mutation with a value class that makes things more OO. I plan to test this against other approaches for overall speed later.
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| object NBodyArray extends App { | |
| def timeCode[T](warmups: Int, timeRuns: Int)(body: => T): Seq[Double] = { | |
| for(_ <- 1 to warmups) body | |
| for(_ <- 1 to timeRuns) yield { | |
| val start = System.nanoTime() | |
| body | |
| (System.nanoTime()-start)*1e-9 | |
| } | |
| } | |
| def printTimeInfo(times: Seq[Double]): Unit = { |
MarkCLewis
/ REAddition.scala
Created
December 7, 2015 15:04
This is a Scala program that runs a Chomsky recursively enumerable grammar. The grammar that it is set up to run adds binary numbers.
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| package grammars | |
| import io.StdIn._ | |
| /** | |
| * @author mlewis | |
| */ | |
| object REAddition extends App { | |
| val prods1 = Map[String, String]( | |
| "N+N1" -> "SN+'NL1", |
MarkCLewis
/ gist:0ca258b4fbd32ad59221
Created
June 25, 2015 14:18
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| import io.Source | |
| val exportRegex = """.*PIMSDB"."(\S+)".*""".r | |
| val exportSource = Source.fromFile("DBExportList.txt") | |
| val exportData = (for(exportRegex(fname) <- exportSource.getLines) yield fname.trim).toArray | |
| exportSource.close | |
| val tableSource = Source.fromFile("TableDefTable.txt") | |
| val tableData = tableSource.getLines.map(_.split("\t")(1).trim.toUpperCase).toArray | |
| tableSource.close |
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