import com.alibaba.fastjson.JSONArray; import com.alibaba.fastjson.JSONObject; import org.junit.Test; import ucar.ma2.Index; import ucar.nc2.NetcdfFile; import ucar.ma2.Array; import java.io.FileWriter; import java.io.IOException; public class NetCDF2JSON { @Test public void test() { cut2Json("V-000.nc", 0, 70, 70, 150); } public void cut2Json(String ncPath, double minLat, double maxLat, double minLon, double maxLon) { try { // 打开 NetCDF 文件 NetcdfFile inputFile = NetcdfFile.open(ncPath); // 获取经纬度变量 Array latArray = inputFile.findVariable("lat").read(); Array lonArray = inputFile.findVariable("lon").read(); Array dataArray = inputFile.findVariable("V").read(); // 获取经纬度索引范围 int minLatIndex = findIndex(latArray, minLat); int maxLatIndex = findIndex(latArray, maxLat); int minLonIndex = findIndex(lonArray, minLon); int maxLonIndex = findIndex(lonArray, maxLon); // 计算 dx 和 dy double dx = (maxLat - minLat) / (minLatIndex - maxLatIndex); double dy = (maxLon - minLon) / (maxLonIndex - minLonIndex); // 创建 Index 对象 Index index = dataArray.getIndex(); JSONArray jsonArray = new JSONArray(); for (int i = maxLatIndex; i <= minLatIndex; i++) { JSONArray rowArray = new JSONArray(); for (int j = minLonIndex; j <= maxLonIndex; j++) { rowArray.add(dataArray.getDouble(index.set(0, i, j))); } jsonArray.add(rowArray); } JSONObject jsonObject = new JSONObject(true); jsonObject.put("minLat", minLat); jsonObject.put("maxLat", maxLat); jsonObject.put("minLon", minLon); jsonObject.put("maxLon", maxLon); jsonObject.put("dx", dx); jsonObject.put("dy", dy); jsonObject.put("data", jsonArray); // 将 JSON 数组写入到文件 try (FileWriter fileWriter = new FileWriter("aaa.json")) { fileWriter.write(jsonObject.toJSONString()); } catch (IOException e) { e.printStackTrace(); } // 关闭文件 inputFile.close(); } catch (Exception e) { e.printStackTrace(); } } // 查找最接近的索引 public int findIndex(Array array, double target) { double[] values = (double[]) array.get1DJavaArray(double.class); int index = 0; double minDifference = Double.MAX_VALUE; for (int i = 0; i < values.length; i++) { double difference = Math.abs(values[i] - target); if (difference < minDifference) { minDifference = difference; index = i; } } return index; } }
标签:findIndex,java,裁切,int,double,NC,import,inputFile From: https://www.cnblogs.com/fangts/p/17654086.html