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How to drop columns by name in a data frame
...t)[!names(dtest) %in% drop_vec]) 108.611 119.4830 124.0865 135.4270 1599.577
subset(dtest, select = -c(x, y)) 102.026 111.2680 115.7035 126.2320 1484.174
Code is below :
dtest <- data.frame(x=1:5, y=2:6, z = 3:7)
drop_vec <- c("x", "y")
null_assign <...
How can I copy the content of a branch to a new local branch?
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Lyle ZLyle Z
1,01999 silver badges77 bronze badges
1
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CMake使用教程 - C/C++ - 清泛网 - 专注C/C++及内核技术
...载它：
运行make package_source可以产生源代码包。（我的电脑上提示找不到合适的zip程序）
D:/Projects/Lab/testngpp/cmake-2.8.1/Tests/Tutorial/Step6/build>make package_sou
rce
Run CPack packaging tool for source...
CPack Error: Cannot find a suitable ZIP program
CPa...
Add shadow to custom shape on Android
...shape android:shape="rectangle" >
<solid android:color="#cc2b2b" />
<corners android:radius="8dp" />
</shape>
</item>
<!-- over left shadow -->
<item>
<shape android:shape="rectangle" >
<...
How can I access my localhost from my Android device?
I'm able to access my laptop web server using the Android emulator, I'm using 10.0.2.2:portno
works well.
39 Answers
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Use latest version of Internet Explorer in the webbrowser control
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Sam Axe
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answered Sep 3 '14 at 17:21
MhmdMhmd
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How do I check for a network connection?
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That is not reliable. read stackoverflow.com/a/25779403/2377343
– T.Todua
Sep 9 '19 at 11:17
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How to override trait function and call it from the overridden function?
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tarkhovtarkhov
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add a comment
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How to find and return a duplicate value in array
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Chris HealdChris Heald
54.7k77 gold badges104104 silver badges124124 bronze badges
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Foreign keys in mongo?
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> db.foo.find()
{ "_id" : ObjectId("4df6539ae90592692ccc9940"), "group" : "phones" }
{ "_id" : ObjectId("4df6540fe90592692ccc9941"), "group" : "phones" }
>db.foo.find({'_id':ObjectId("4df6539ae90592692ccc9940")})
{ "_id" : ObjectId("4df6539ae90592692ccc9940"), "group" : "ph...