java - 使用java计算两个csv GPS点之间的距离

Question

我正在尝试计算 csv 文件中存储的两个 GPS 点之间的距离......

这是我代码的一部分...问题出在 latitude2 和 longitude 我不知道如何使用正确的经度和纬度来实现它们，请帮忙!

                BufferedReader reader = new BufferedReader(new FileReader(file));
    try {
        /* First line of the data file is the header */
        String line = reader.readLine();
        System.out.println("Header: " + line);
        boolean foundAnyRowHigherThan5 = false;
        for (line = reader.readLine(); line != null; line = reader.readLine()) {
            if (line.trim().length() > 0) { // skip blank lines

                String tokens[] = line.split("\\,");
                String name1 = tokens[0].trim();
                String name2 = tokens[1].trim();
                double latitude = Double.parseDouble(tokens[2]);
                double longitude = Double.parseDouble(tokens[3]);

                double latitude2 = latitude+?; // i dont know how to implement
                double longitude2 = longitude+?;  // i dont know how to implement them
                String speedString = tokens[5].trim();
                double dist = Double.parseDouble(tokens[4]);
                float speedFloat = Float.parseFloat(speedString);

              if(foundAnyRowHigherThan5 || speedFloat > 5.0) {
                // a partir de ce point on ajoutera touts les points ,
                if(!foundAnyRowHigherThan5) {
                  foundAnyRowHigherThan5 = true;
                }

                /* Longitude (= x coord) first ! */
                Point point = geometryFactory.createPoint(new Coordinate(longitude, latitude));

                featureBuilder.add(point);

                double earthRadius = 6371; //kilometers
                double dLat = Math.toRadians(latitude-latitude2);
                double dLng = Math.toRadians(longitude-longitude2);
                double a = Math.sin(dLat/2) * Math.sin(dLat/2) +
                           Math.cos(Math.toRadians(latitude)) * Math.cos(Math.toRadians(latitude2)) *
                           Math.sin(dLng/2) * Math.sin(dLng/2);
                double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
                 dist = (double) (earthRadius * c);


                featureBuilder.add(name1);
                featureBuilder.add(name2);

                featureBuilder.add(speedString);
                featureBuilder.add(dist);
                SimpleFeature feature = featureBuilder.buildFeature(null);

                features.add(feature);


                }
            }
        }
    } finally {
        reader.close();
    }

Answer 1

有不同的方法可以解决这个问题，但我会留在你的代码片段中。

boolean checker = true;
double currentLongitude = 0;
double currentLatitude = 0;
    for (....) {
                ....
    if(checker){
            String currentTokens[] = line.split("\\,");
            String currentName1 = currentTokens[0].trim();
            String currentName2 = currentTokens[1].trim();
            currentLatitude = Double.parseDouble(currentTokens[2]);
            currentLongitude = Double.parseDouble(currentTokens[3]);
            checker = false;
            continue;
            } 


   String tokens[] = line.split("\\,");
   String name1 = tokens[0].trim();
   String name2 = tokens[1].trim();
   double latitude = Double.parseDouble(tokens[2]);
   double longitude = Double.parseDouble(tokens[3]);

   double latitude2 = currentLatitude - latitude; 
   double longitude2 = currentLongitude - longitude;
   .....
   currentLatitude = latitude;
   currentLongitude = longitude;  
}