Arthur BrownArvin TangSam KristoffAndrew Holzer
Published © MIT

Estimating Pi with a Cora Z7 Running Linux

How should we go about figuring out how fast the Cora Z7 is? What about using both CPU cores? What about using a full OS?

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Estimating Pi with a Cora Z7 Running Linux

Things used in this project

Software apps and online services

Vivado WebPACK
PetaLinux
AMD PetaLinux

Story

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Code

main.go

Go
Go application source code. To be built for ARM architecture to run in a Cora Petalinux environment.
package main

import (
	"fmt"
	"math/rand"
	"runtime"
	"time"
)

func PI(samples int) float64 {
	var inside int = 0

	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	for i := 0; i < samples; i++ {
		x := r.Float64()
		y := r.Float64()
		if (x*x + y*y) < 1 {
			inside++
		}
	}

	ratio := float64(inside) / float64(samples)

	return ratio * 4
}

func MultiPI(samples int) float64 {
	cpus := runtime.NumCPU()

	threadSamples := samples / cpus
	results := make(chan float64, cpus)

	for j := 0; j < cpus; j++ {
		go func() {
			var inside int
			r := rand.New(rand.NewSource(time.Now().UnixNano()))
			for i := 0; i < threadSamples; i++ {
				x, y := r.Float64(), r.Float64()

				if x*x+y*y <= 1 {
					inside++
				}
			}
			results <- float64(inside) / float64(threadSamples) * 4
		}()
	}

	var total float64
	for i := 0; i < cpus; i++ {
		total += <-results
	}

	return total / float64(cpus)
}

func init() {
	runtime.GOMAXPROCS(runtime.NumCPU())
}

func main() {
	fmt.Println("Running Monte Carlo simulations ...\n")

	var iterations = 524287500
	fmt.Println(iterations, "iterations in a single thread")
	start := time.Now()
	fmt.Println("calculated", PI(iterations))
	t := time.Now()
	elapsed := t.Sub(start)
	fmt.Println("in", elapsed)

	fmt.Println()
	fmt.Println(iterations, "iterations in a multiple threads")
	start2 := time.Now()
	fmt.Println("calculated", MultiPI(iterations))
	t2 := time.Now()
	elapsed2 := t2.Sub(start2)
	fmt.Println("in", elapsed2)
}

Credits

Arthur Brown

Arthur Brown

14 projects • 30 followers
Applications engineer and digital logic geek
Arvin Tang

Arvin Tang

2 projects • 5 followers
Sam Kristoff

Sam Kristoff

35 projects • 53 followers
R&D Director at NI
Andrew Holzer

Andrew Holzer

2 projects • 2 followers
Thanks to Sam Bobrowicz and Soroush Pour.

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