Weather routing: Difference between revisions

Given the above information and a specific path, progress and arrival time are determined. The weather routing problem, conversely, is to determine the path which results in the earliest arrival time.

 

 

=={{header|Julia}}==

Brute force optimization search, practical for shorter path lengths, but would require a better algorithm for paths over twice this size.

 

using DelimitedFiles

println("The route taking the least time found was:\n ", tp.path,

"\nwhich has duration $(div(tp.duration, 60)) hours, $(rem(tp.duration, 60)) minutes.")

The polar CSV file used for this solution, named polar.csv, is as follows. Note that this is a very detailed

polar, chosen to stress the testing of the code. Most polar files are far smaller,

Point{2,Int64}[[1, 4], [1, 5], [2, 6], [3, 7], [4, 7], [5, 7], [6, 7], [7, 7], [8, 6], [8, 5], [9, 4]]

which has duration 4.0 hours, 43.697879668707344 minutes.

</pre>

 

 

As you'd expect, this takes many times longer than Julia to run (about 24.5 minutes versus 3 minutes 20 seconds) but gets there in the end :)

 

/*

var getPolarData = Fn.new { |fileName|

var lines = File.read(fileName).split("\n")

var winds = header[1..-1].map { |x| Num.fromString(x) }.toList

var degrees = []

var speeds = []

for (line in lines[1..-1]) {

if (line == "") break // ignore final blank line if there is one

var cols = line.split(";")

var distance = h[0]

var dir = h[1]

// minutes/s * m / (knots * (m/s / knot)) = minutes

return (1 / 60) * distance / (vel * 1.94384)

/*

Class that represents a routing problem and requiring the following parameters:

* timeframe: a vector of sequential timeslices for the ocean region

* obstacleindices: the Cartesian indices in each timeslice for

var timedPaths = [TimedPath.new(0, [rp.start])]

var completed = false

var minPath = TimedPath.new(1000, [])

for (i in 0...1000) {

var tp = minimumTimeRoute.call(routeProb, sp, false)

System.print("The route taking the least time found was:\n %(tp.path) \nwhich has duration " +

 

{{out}}