Centroid calculation for alert distance

This commit is contained in:
Dan Paulat 2022-10-15 09:43:47 -05:00
parent a3d007d8c4
commit 5784abc117
3 changed files with 91 additions and 19 deletions

View file

@ -48,6 +48,10 @@ public:
GeographicLib::Geodesic geodesic_;
std::unordered_map<types::TextEventKey,
common::Coordinate,
types::TextEventHash<types::TextEventKey>>
centroidMap_;
std::unordered_map<types::TextEventKey,
double,
types::TextEventHash<types::TextEventKey>>
@ -173,30 +177,43 @@ void AlertModel::HandleAlert(const types::TextEventKey& alertKey)
double distanceInMeters;
if (!p->textEventKeys_.contains(alertKey))
{
beginInsertRows(QModelIndex(), 0, 0);
// Get the most recent segment for the event
auto alertMessages =
manager::TextEventManager::Instance().message_list(alertKey);
std::shared_ptr<const awips::Segment> alertSegment =
alertMessages.back()->segments().back();
p->textEventKeys_.push_back(alertKey);
if (alertSegment->codedLocation_.has_value())
{
// Update centroid and distance
common::Coordinate centroid =
common::GetCentroid(alertSegment->codedLocation_->coordinates());
p->geodesic_.Inverse(p->previousPosition_.latitude_,
p->previousPosition_.longitude_,
0.0, // TODO: textEvent->latitude(),
0.0, // TODO: textEvent->longitude(),
centroid.latitude_,
centroid.longitude_,
distanceInMeters);
p->distanceMap_[alertKey] = distanceInMeters;
p->centroidMap_.insert_or_assign(alertKey, centroid);
p->distanceMap_.insert_or_assign(alertKey, distanceInMeters);
}
else if (!p->centroidMap_.contains(alertKey))
{
// The alert has no location, so provide a default
p->centroidMap_.insert_or_assign(alertKey, common::Coordinate {0.0, 0.0});
p->distanceMap_.insert_or_assign(alertKey, 0.0);
}
// Update row
if (!p->textEventKeys_.contains(alertKey))
{
beginInsertRows(QModelIndex(), 0, 0);
p->textEventKeys_.push_back(alertKey);
endInsertRows();
}
else
{
p->geodesic_.Inverse(p->previousPosition_.latitude_,
p->previousPosition_.longitude_,
0.0, // TODO: textEvent->latitude(),
0.0, // TODO: textEvent->longitude(),
distanceInMeters);
const int row = p->textEventKeys_.indexOf(alertKey);
QModelIndex topLeft = createIndex(row, kFirstColumn);
QModelIndex bottomRight = createIndex(row, kLastColumn);
@ -213,12 +230,17 @@ void AlertModel::HandleMapUpdate(double latitude, double longitude)
for (const auto& textEvent : p->textEventKeys_)
{
p->geodesic_.Inverse(latitude,
longitude,
0.0, // TODO: textEvent->latitude(),
0.0, // TODO: textEvent->longitude(),
distanceInMeters);
p->distanceMap_[textEvent] = distanceInMeters;
auto& centroid = p->centroidMap_.at(textEvent);
if (centroid != common::Coordinate {0.0, 0.0})
{
p->geodesic_.Inverse(latitude,
longitude,
centroid.latitude_,
centroid.longitude_,
distanceInMeters);
p->distanceMap_.insert_or_assign(textEvent, distanceInMeters);
}
}
p->previousPosition_ = {latitude, longitude};

View file

@ -1,6 +1,7 @@
#pragma once
#include <string>
#include <vector>
namespace scwx
{
@ -43,6 +44,16 @@ enum class DistanceType
Miles
};
/**
* Calculate the geographic midpoint of a set of coordinates. Uses Method A
* described at http://www.geomidpoint.com/calculation.html.
*
* @param coordinates Set of unique coordinates
*
* @return Centroid
*/
Coordinate GetCentroid(const std::vector<Coordinate>& coordinates);
std::string
GetLatitudeString(double latitude,
DegreeStringType type = DegreeStringType::Decimal);

View file

@ -2,6 +2,7 @@
#include <scwx/common/characters.hpp>
#include <format>
#include <numbers>
namespace scwx
{
@ -12,6 +13,44 @@ static std::string GetDegreeString(double degrees,
DegreeStringType type,
const std::string& suffix);
Coordinate GetCentroid(const std::vector<Coordinate>& coordinates)
{
double x = 0.0;
double y = 0.0;
double z = 0.0;
for (const Coordinate& c : coordinates)
{
// Convert latitude and longitude to radians
double latitudeRadians = c.latitude_ * std::numbers::pi / 180.0;
double longitudeRadians = c.longitude_ * std::numbers::pi / 180.0;
// Convert latitude and longitude to Cartesian coordinates
double x1 = std::cos(latitudeRadians) * std::cos(longitudeRadians);
double y1 = std::cos(latitudeRadians) * std::sin(longitudeRadians);
double z1 = std::sin(latitudeRadians);
// Combine with accumulators
x += x1;
y += y1;
z += z1;
}
// Compute averages
x /= coordinates.size();
y /= coordinates.size();
z /= coordinates.size();
// Convert Cartesian coordinates back to latitude and longitude
double hyp = std::sqrt(x * x + y * y);
double latitudeRadians = std::atan2(z, hyp);
double longitudeRadians = std::atan2(y, x);
// Return latitude and longitude in degrees
return {latitudeRadians * 180.0 / std::numbers::pi,
longitudeRadians * 180.0 / std::numbers::pi};
}
std::string GetLatitudeString(double latitude, DegreeStringType type)
{
std::string suffix {};