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Subset of rows containing NA (missing) values in a chosen column of a data frame
....na() instead. This should do it:
new_DF <- DF[rowSums(is.na(DF)) > 0,]
or in case you want to check a particular column, you can also use
new_DF <- DF[is.na(DF$Var),]
In case you have NA character values, first run
Df[Df=='NA'] <- NA
to replace them with missing values.
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How do I wait for an asynchronously dispatched block to finish?
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304
Trying to use a dispatch_semaphore. It should look something like this:
dispatch_semaphore_t s...
What's the best way to do “application settings” in Android? [closed]
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150
Many applications may provide a way to capture user preferences on the settings of a specific ap...
UIRefreshControl on UICollectionView only works if the collection fills the height of the container
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LarryLarry
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No line-break after a hyphen
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590
Try using the non-breaking hyphen &#8209;. I've replaced the dash with that character in you...
Javascript: How to detect if browser window is scrolled to bottom?
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answered Feb 25 '12 at 0:03
mVChrmVChr
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Count immediate child div elements using jQuery
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answered Oct 30 '08 at 15:49
Garry ShutlerGarry Shutler
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Calc of max, or max of calc in CSS
... them.
Therefore the original example can be written as:
max-width: max(500px, 100% - 80px);
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Subscript and Superscript a String in Android
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160
((TextView)findViewById(R.id.text)).setText(Html.fromHtml("X<sup>2</sup>"));
or
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Android应用内存泄露分析、改善经验总结 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...果明显：完全退出应用时，手动触发GC，从原来占有内存100多M降到低于20M...前言
  通过这几天对好几个应用的内存泄露检测和改善，效果明显：
完全退出应用时，手动触发GC，从原来占有内存100多M降到低于20M；
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