Question

我有一个名为“ weights”的数据集，我想知道编写以下代码的最有效方法是什么：

public class MainActivity extends AppCompatActivity {

static AudioManager mAudioManager;
static ComponentName mReceiverComponent;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
    mReceiverComponent = new ComponentName(this, HeadsetBtnReceiver.class);
    mAudioManager.registerMediaButtonEventReceiver(mReceiverComponent);

}
@Override
public void onResume() {
    super.onResume();
}

@Override
public void onPause() {
    super.onPause();
}

@Override
public void onBackPressed() {
    Log.e("Udp", "Backpress MainActivity");
    finish();
}

@Override
public void onDestroy() {
    Log.e("UDP svc", "Destroying MainActivity");
    mAudioManager.unregisterMediaButtonEventReceiver(mReceiverComponent);
    finish();
    super.onDestroy();
}

public static class HeadsetBtnReceiver extends BroadcastReceiver {

    // Constructor is mandatory

    public HeadsetBtnReceiver()
    {
        super ();
    }
    @Override
    public void onReceive(Context context, Intent intent) {
        String intentAction = intent.getAction();
        Log.e("Udp svc", intentAction.toString() + " happened");
        if (!Intent.ACTION_MEDIA_BUTTON.equals(intentAction)) {
            Log.e("Udp svc", "no media button information");
            return;
        }
        KeyEvent event = (KeyEvent) intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);
        if (event == null) {
            Log.e("Udp svc", "no keypress");
            return;
        }

        KeyEvent key = (KeyEvent) intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);
        Log.e("UDP svc", "KeyEvent : ");

        if(key.getAction() == KeyEvent.ACTION_UP) {
            int keycode = key.getKeyCode();
            if(keycode == KeyEvent.KEYCODE_MEDIA_NEXT) {
                Log.e("Udp svc", "Next Pressed");
            } else if(keycode == KeyEvent.KEYCODE_MEDIA_PREVIOUS) {
                Log.e("Udp svc", "Previous pressed");
            } else if(keycode == KeyEvent.KEYCODE_HEADSETHOOK) {
                Log.e("Udp svc", "Head Set Hook pressed");
            }
        }
    }
}

谢谢。我一直在尝试使用带有独特（weights $ Region）的for循环来填充这7个数据帧。

Answer 1

简而言之，将split的数据按区域划分为子集，并对每个数据lapply进行treemap：

mylist <- split(weights, weights$Region)
result <- lapply(mylist, treemap::treemap, index=c("Level.0","Level.1"), vSize="X2015", type="index")

更新：太好了！这个问题要求“高效”的代码编写方式，而我的带有lapply的2线式输给了2个for循环，一个cbind和一个assign的答案。好吧，你能做什么...：）

Answer 2

正如其他人指出的那样，很难弄清，d3treeR软件包在CRAN上也不可用，因此我不确定这是否可行。使用purrr::map()

library(tidyverse)
library(d3treeR)

myfun <- function(weights, Region, x){
  weights %>% 
    filter(Region %in% x) %>%
    treemap(index=c("Level.0","Level.1"), vSize="X2015", type="index")
}

Regions <- c("Canada", "Ontario", "Newfoundland and Labrador", "Prince Edward Island", "Nova Scotia", "New Brunswick", "Quebec")

results <- map(Regions, myfun, weights = weights, Region = Region)

Answer 3

类似这样的东西：

Bar

如果是这样的话

    x <- c("CAN",  "ON",  "NL", "PE", "NS", "NB", "QC")
    weights <- as.data.frame(cbind(weights=rep(c(1,2,3), 7), Region=x))

    for(i in x){
      y <- weights[weights$Region == i, ]
      assign(i, y) 
    }

创建新的数据框并在R中应用函数进行循环

3 个答案: