Question

我正在完成一项任务，并在某一时刻陷入困境。我收到一个带有一系列电台的.txt文件，我应该使用给我的GPS坐标来绘制电台名称，但是我无法将这些坐标转换为XY坐标{{{ 1}}使用。此外，GPS坐标以JPanel s写入，但double s中的XY坐标。我怎样才能做到这一点？

这里的代码不起作用。

int

我试图使用以下方式绘制它们：

     void extents() {
 minLong = Double.MAX_VALUE;
 minLat = Double.MAX_VALUE;
 maxLong = -Double.MIN_VALUE;
 maxLat = -Double.MIN_VALUE;

for(Station station : stations){

    if(station.getLatitude()>maxLat){
        maxLat = station.getLongitude();
        maxLong = station.getLongitude();
    }
    if(station.getLatitude()<minLat){
        minLat = station.getLongitude();
        minLong = station.getLongitude();
    }
    if(station.getLongitude()>maxLong){
        maxLong = station.getLongitude();
    }
    if(station.getLongitude()<minLong){
        minLong = station.getLongitude();
    }
}

我现在为每个电台获得不同的坐标，但是它们仍然太近，这意味着它们没有缩放到for (int i = 0; i < stations.size(); i++) { double scalingFactorx = width/(maxLat - minLat); double scalingFactory = height/(maxLong - minLong); double scalingFactor = Math.min(scalingFactorx, scalingFactory); double drawingX = stations.get(i).getLatitude() * scalingFactor; double drawingY = stations.get(i).getLongitude() * scalingFactor; double drawingY2 = height - drawingY; gr.drawString(stations.get(i).getName(), (int)drawingX/100, (int)drawingY2/200); }。

谢谢！

Answer 1

嗯，首先，您应该将最小值和最大值设为实际的最小值和最大值：

double minLong = Double.MAX_VALUE;
double minLat = Double.MAX_VALUE;
double maxLong = -Double.MIN_VALUE;
double maxLat = -Double.MIN_VALUE;

for(Station station : stations){

    if(station.getLatitude()>maxLat){
        maxLat = station.getLongitude();
        maxLong = station.getLongitude();
    }
    if(station.getLatitude()<minLat){
        minLat = station.getLongitude();
        minLong = station.getLongitude();
    }
    if(station.getLongitude()>maxLong){
        maxLong = station.getLongitude();
    }
    if(station.getLongitude()<minLong){
        minLong = station.getLongitude();
    }
}

然后你可以在你的绘制方法中做到这一点：

for (int i = 0; i < stations.size(); i++) {

    double scalingFactorx = width/(maxLat - minLat);
    double scalingFactory = height/(maxLong - minLong);
    double scalingFactor = Math.min(scalingFactorx, scalingFactory);

    double drawingX = (stations.get(i).getLatitude() - minLat)/(maxLat-minLat);
    double drawingY = (stations.get(i).getLongitude() - minLong)/(maxLong-minLong);
    //double drawingY2 = height - drawingY; This line isn't needed. It causes the text to be drawn outside the jpanel.
    gr.drawString(stations.get(i).getName(), (int)drawingX, (int)drawingY);

}

现在，它的作用是找到最右边和最左边的站点以及最高和最低位置，然后根据需要调整所有内容。

Answer 2

   for (int i = 0; i < stations.size(); i++) {

    extents();

    scalingFactorx = width/(maxLat - minLat);
    scalingFactory = height/(maxLong - minLong);
    scalingFactor = Math.min(scalingFactorx, scalingFactory);

    drawingX = (stations.get(i).getLatitude() - minLat)   * scalingFactorx;
    drawingY = (stations.get(i).getLongitude() - minLong)  * scalingFactory;
    drawingY2 = height - drawingY; 
    gr.drawString(stations.get(i).getName(), (int)drawingX, (int)drawingY2);

这样的事情应该解决它。

Java Swing - 在JPanel上使用GPS坐标绘制工作站名称

2 个答案: