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search for shortest path algorithm

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This commit is contained in:
Artyom Degtyarev 2023-03-09 16:03:48 +03:00
parent 1b6a41c728
commit 2bce369c5d
2 changed files with 60 additions and 15 deletions
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38
kmath-trajectory/src/commonMain/kotlin/space/kscience/kmath/trajectory/DubinsObstacle.kt
View File

@ -111,13 +111,24 @@ public class DubinsObstacle(
else { else {
for (i in this.circles.indices) { for (i in this.circles.indices) {
if (this.circles[i] == circle) { if (this.circles[i] == circle) {
return DubinsTangent(this.circles[i], if (i > 0) {
this.circles[i-1], return DubinsTangent(this.circles[i],
this, this.circles[i-1],
this, this,
LineSegment2D(this.tangents[i-1].lineSegment.end, this,
this.tangents[i-1].lineSegment.begin), LineSegment2D(this.tangents[i-1].lineSegment.end,
DubinsPath.toSimpleTypes(route)) this.tangents[i-1].lineSegment.begin),
DubinsPath.toSimpleTypes(route))
}
else {
return DubinsTangent(this.circles[0],
this.circles.last(),
this,
this,
LineSegment2D(this.tangents.last().lineSegment.end,
this.tangents.last().lineSegment.begin),
DubinsPath.toSimpleTypes(route))
}
} }
} }
} }
@ -156,7 +167,7 @@ public fun LineSegment2D.intersectCircle(circle: Circle2D): Boolean {
val a = (this.begin.x - this.end.x).pow(2.0) + (this.begin.y - this.end.y).pow(2.0) val a = (this.begin.x - this.end.x).pow(2.0) + (this.begin.y - this.end.y).pow(2.0)
val b = 2 * ((this.begin.x - this.end.x) * (this.end.x - circle.center.x) + val b = 2 * ((this.begin.x - this.end.x) * (this.end.x - circle.center.x) +
(this.begin.y - this.end.y) * (this.end.y - circle.center.y)) (this.begin.y - this.end.y) * (this.end.y - circle.center.y))
val c = (this.end.x - circle.center.x).pow(2.0) + (this.end.y - circle.center.y) - val c = (this.end.x - circle.center.x).pow(2.0) + (this.end.y - circle.center.y).pow(2.0) -
circle.radius.pow(2.0) circle.radius.pow(2.0)
val d = b.pow(2.0) - 4 * a * c val d = b.pow(2.0) - 4 * a * c
if (d < 1e-6) { if (d < 1e-6) {
@ -289,7 +300,7 @@ public fun allFinished(paths: List<List<DubinsTangent>>,
public fun pathLength(path: List<DubinsTangent>): Double { public fun pathLength(path: List<DubinsTangent>): Double {
val tangentsLength = path.sumOf{norm(it.lineSegment.end - it.lineSegment.begin)} val tangentsLength = path.sumOf{norm(it.lineSegment.end - it.lineSegment.begin)}
val arcsLength = buildList<Double>{ val arcsLength = buildList<Double>{
for (i in 1..path.size) { for (i in 1..path.lastIndex) {
add(arcLength(path[i].startCircle, add(arcLength(path[i].startCircle,
path[i-1].lineSegment.end, path[i-1].lineSegment.end,
path[i].lineSegment.begin, path[i].lineSegment.begin,
@ -366,13 +377,14 @@ public fun findAllPaths(
} }
var nextTangents = outerTangents(currentObstacle, nextObstacle) var nextTangents = outerTangents(currentObstacle, nextObstacle)
for (pathType in nextTangents.keys) { for (pathType in DubinsPath.Type.values()) {
for (obstacle in obstacles) { for (obstacle in obstacles) {
// in Python code here try/except was used, but seems unneeded // in Python code here try/except was used, but seems unneeded
if (nextTangents[pathType]!!.intersectObstacle(obstacle)) { if (nextTangents.containsKey(pathType)) {
nextTangents.remove(pathType) if (nextTangents[pathType]!!.intersectObstacle(obstacle)) {
nextTangents.remove(pathType)
}
} }
} }
} }
nextTangents = if (nextObstacle == finalObstacle) { nextTangents = if (nextObstacle == finalObstacle) {

37
kmath-trajectory/src/commonTest/kotlin/space/kscience/kmath/trajectory/DubinsTest.kt
View File

@ -33,8 +33,41 @@ class DubinsTest {
finalRadius, finalRadius,
obstacles) obstacles)
val length = pathLength(shortestPath(outputTangents)) val length = pathLength(shortestPath(outputTangents))
TODO("fix negative indices in boundaryTangents and accomplish test") println(length)
assertTrue(false) }
@Test
fun secondPath() {
val startPoint = vector(-5.0, -1.0)
val startDirection = vector(1.0, 1.0)
val startRadius = 0.5
val finalPoint = vector(20.0, 4.0)
val finalDirection = vector(1.0, -1.0)
val finalRadius = 0.5
val obstacles = listOf(
DubinsObstacle(listOf(
Circle2D(vector(1.0, 6.5), 0.5),
Circle2D(vector(2.0, 1.0), 0.5),
Circle2D(vector(6.0, 0.0), 0.5),
Circle2D(vector(5.0, 5.0), 0.5)
)), DubinsObstacle(listOf(
Circle2D(vector(10.0, 1.0), 0.5),
Circle2D(vector(16.0, 0.0), 0.5),
Circle2D(vector(14.0, 6.0), 0.5),
Circle2D(vector(9.0, 4.0), 0.5)
))
)
val outputTangents = findAllPaths(
startPoint,
startDirection,
startRadius,
finalPoint,
finalDirection,
finalRadius,
obstacles)
val length = pathLength(shortestPath(outputTangents))
println(length)
} }
@Test @Test
fun outerTangentsTest1() { fun outerTangentsTest1() {