The Computer Language
Benchmarks Game

n-body VW Smalltalk program

source code

"* The Computer Language Benchmarks Game
    https://salsa.debian.org/benchmarksgame-team/benchmarksgame/
    contributed by Isaac Gouy *"!

Smalltalk defineClass: #NBodySystem
    superclass: #{Core.Object}
    indexedType: #none
    private: false
    instanceVariableNames: 'bodies '
    classInstanceVariableNames: ''
    imports: ''
    category: 'benchmarks game'!

Smalltalk defineClass: #Body
    superclass: #{Core.Object}
    indexedType: #none
    private: false
    instanceVariableNames: 'x y z vx vy vz mass '
    classInstanceVariableNames: ''
    imports: ''
    category: 'benchmarks game'!

Smalltalk.Core defineClass: #BenchmarksGame
    superclass: #{Core.Object}
    indexedType: #none
    private: false
    instanceVariableNames: ''
    classInstanceVariableNames: ''
    imports: ''
    category: ''!

!Body class methodsFor: 'constants'!

daysPerYear
   ^365.24d0!

sun
   ^self new
      x: 0.0d0
      y: 0.0d0
      z: 0.0d0
      vx: 0.0d0
      vy: 0.0d0
      vz: 0.0d0
      mass: self solarMass!

uranus
   ^self new
      x: 1.28943695621391310d1
      y: -1.51111514016986312d1
      z: -2.23307578892655734d-1
      vx: 2.96460137564761618d-3 * self daysPerYear
      vy: 2.37847173959480950d-3 * self daysPerYear
      vz: -2.96589568540237556d-5 * self daysPerYear
      mass: 4.36624404335156298d-5 * self solarMass!

saturn
   ^self new
      x: 8.34336671824457987d0
      y: 4.12479856412430479d0
      z: -4.03523417114321381d-1
      vx: -2.76742510726862411d-3 * self daysPerYear
      vy: 4.99852801234917238d-3 * self daysPerYear
      vz: 2.30417297573763929d-5 * self daysPerYear
      mass: 2.85885980666130812d-4 * self solarMass!

solarMass
   ^4.0d0 * self pi * self pi!

pi
   ^3.141592653589793d0!

jupiter
   ^self new
      x: 4.84143144246472090d0
      y: -1.16032004402742839d0
      z: -1.03622044471123109d-1
      vx: 1.66007664274403694d-3 * self daysPerYear
      vy: 7.69901118419740425d-3 * self daysPerYear
      vz: -6.90460016972063023d-5 * self daysPerYear
      mass: 9.54791938424326609d-4 * self solarMass!

neptune
   ^self new
      x: 1.53796971148509165d1
      y: -2.59193146099879641d1
      z: 1.79258772950371181d-1
      vx: 2.68067772490389322d-3 * self daysPerYear
      vy: 1.62824170038242295d-3 * self daysPerYear
      vz: -9.51592254519715870d-5 * self daysPerYear
      mass: 5.15138902046611451d-5 * self solarMass! !


!Body methodsFor: 'accessing'!

z
   ^z!

x
   ^x!

mass
   ^mass!

x: d1 y: d2 z: d3 vx: d4 vy: d5 vz: d6 mass: d7
   x := d1.
   y := d2. 
   z := d3. 
   vx := d4.
   vy := d5.
   vz := d6.
   mass := d7!

y
   ^y! !

!Body methodsFor: 'nbody'!

offsetMomentum: anArray 
   | m |
   m := self class solarMass.
   vx := (anArray at: 1) negated / m.
   vy := (anArray at: 2) negated / m.
   vz := (anArray at: 3) negated / m!

decreaseVelocity: dx y: dy z: dz m: m
   vx := vx - (dx * m).
   vy := vy - (dy * m).
   vz := vz - (dz * m)!

positionAfter: dt
   x := x + (dt * vx).
   y := y + (dt * vy).
   z := z + (dt * vz)!

and: aBody velocityAfter: dt        
   | dx dy dz distance mag |
   dx := x - aBody x.
   dy := y - aBody y.
   dz := z - aBody z.
   
   distance := ((dx*dx) + (dy*dy) + (dz*dz)) sqrt.
   mag := dt / (distance * distance * distance).

   self decreaseVelocity: dx y: dy z: dz m: aBody mass * mag.   
   aBody increaseVelocity: dx y: dy z: dz m: mass * mag!

potentialEnergy: aBody
   | dx dy dz distance |
   dx := x - aBody x.
   dy := y - aBody y.
   dz := z - aBody z.

   distance := ((dx*dx) + (dy*dy) + (dz*dz)) sqrt.
   ^mass * aBody mass / distance!

addMomentumTo: anArray
   anArray at: 1 put: (anArray at: 1) + (vx * mass).
   anArray at: 2 put: (anArray at: 2) + (vy * mass).
   anArray at: 3 put: (anArray at: 3) + (vz * mass).
   ^anArray!

increaseVelocity: dx y: dy z: dz m: m
   vx := vx + (dx * m).
   vy := vy + (dy * m).
   vz := vz + (dz * m)!

kineticEnergy
   ^0.5d0 * mass * ((vx * vx) + (vy * vy) + (vz * vz))! !


!NBodySystem methodsFor: 'initialize-release'!

initialize
   bodies := OrderedCollection new
      add: Body sun; add: Body jupiter; add: Body saturn;
      add: Body uranus; add: Body neptune; yourself.

   bodies first offsetMomentum:
      (bodies inject: (Array with: 0.0d0 with: 0.0d0 with: 0.0d0)
         into: [:m :each | each addMomentumTo: m])! !

!NBodySystem methodsFor: 'nbody'!

after: dt
   1 to: bodies size do: [:i|
      i+1 to: bodies size do: [:j|                            
         (bodies at: i) and: (bodies at: j) velocityAfter: dt].
   ].   
   bodies do: [:each| each positionAfter: dt]!

energy
   | e |
   e := 0.0d0.
   1 to: bodies size do: [:i|       
      e := e + (bodies at: i) kineticEnergy.

      i+1 to: bodies size do: [:j| 
         e := e - ((bodies at: i) potentialEnergy: (bodies at: j))].
   ].
   ^e! !

!Core.BenchmarksGame class methodsFor: 'initialize-release'!

do: n
   bodies := NBodySystem new initialize.
   Stdout print: bodies energy digits: 9; nl.
   n timesRepeat: [bodies after: 0.01d0].
   Stdout print: bodies energy digits: 9; nl.

   ^''! !

!Core.Stream methodsFor: 'benchmarks game'!

nl
   self nextPut: Character lf!

print: number digits: decimalPlaces
   self nextPutAll: 
      ((number asFixedPoint: decimalPlaces) printString copyWithout: $s)! !


    

notes, command-line, and program output

NOTES:
64-bit Ubuntu quad core
VisualWorks® 8.3 Aug 19 2017




Sun, 25 Oct 2020 03:47:20 GMT

MAKE:
cp /opt/src/vw8.3pul/image/visualnc64.im nbody.vw_run.im
/opt/src/vw8.3pul/bin/visual nbody.vw_run.im -nogui -pcl MatriX -filein nbody.vw -doit 'ObjectMemory snapshotThenQuit'

Autoloading MatriX from $(VISUALWORKS)/preview/matrix/MatriX.pcl
Autoloading Xtreams-Support from $(VISUALWORKS)/xtreams/Xtreams-Support.pcl
Autoloading Xtreams-Core from $(VISUALWORKS)/xtreams/Xtreams-Core.pcl
Autoloading Xtreams-Terminals from $(VISUALWORKS)/xtreams/Xtreams-Terminals.pcl
Autoloading Xtreams-Transforms from $(VISUALWORKS)/xtreams/Xtreams-Transforms.pcl
Autoloading Xtreams-Substreams from $(VISUALWORKS)/xtreams/Xtreams-Substreams.pcl
Autoloading Xtreams-Multiplexing from $(VISUALWORKS)/xtreams/Xtreams-Multiplexing.pcl
Filing in from:
	nbody.vw
Body class<constants
Body<accessing
Body<nbody
NBodySystem<initialize-release
NBodySystem<nbody
BenchmarksGame class<initialize-release
Stream<benchmarks game
Do you want to add Root.Smalltalk.Core.Stream>>nl to the previously unchanged package, Collections-Streams
						OK to continue?
/home/dunham/all-benchmarksgame/benchmarksgame_i53330/nbody/tmp/nbody.vw_run.im created at October 24, 2020 8:47:05 PM
5.89s to complete and log all make actions

COMMAND LINE:
/opt/src/vw8.3pul/bin/visual nbody.vw_run.im -nogui -evaluate "BenchmarksGame do: 50000000"

PROGRAM OUTPUT:
-0.169075164
-0.169059907