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How does one reorder columns in a data frame?
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Your dataframe has four columns like so df[,c(1,2,3,4)].
Note the first comma means keep all the rows, and the 1,2,3,4 refers to the columns.
To change the order as in the above question do df2[,c(1,3,2,4)]
If you want to output this file as a csv, do write.csv(df2, file...
Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...o similar questions scattered around this site.
tmp <- data.frame(x=gl(2,3, labels=letters[24:25]),
y=gl(3,1,6, labels=letters[1:3]),
z=c(1,2,3,3,3,2))
Using the tidyverse:
The new cool new way to do this is with pivot_wider from tidyr 1.0.0. It returns a...
How do I find the duplicates in a list and create another list with them?
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How can building a heap be O(n) time complexity?
...ap. The work required for the siftDown approach is given by the sum
(0 * n/2) + (1 * n/4) + (2 * n/8) + ... + (h * 1).
Each term in the sum has the maximum distance a node at the given height will have to move (zero for the bottom layer, h for the root) multiplied by the number of nodes at that hei...
How to do multiple arguments to map function where one remains the same in python?
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One option is a list comprehension:
[add(x, 2) for x in [1, 2, 3]]
More options:
a = [1, 2, ...
What is the formal difference in Scala between braces and parentheses, and when should they be used?
..., and only if, the method expects a single parameter. For example:
List(1, 2, 3).reduceLeft{_ + _} // valid, single Function2[Int,Int] parameter
List{1, 2, 3}.reduceLeft(_ + _) // invalid, A* vararg parameter
However, there’s more you need to know to better grasp these rules.
Increased compile c...
CMake使用教程 - C/C++ - 清泛网 - 专注C/C++及内核技术
...可以下载zip压缩的绿色版本，还可以下载源代码。
（2）运行cmake的方法。（GUI、命令行）
http://www.cmake.org/cmake/help/runningcmake.html
CMake使用步骤：
运行GUI的cmake界面：
cmake-2.8.1-win32-x86/bin/cmake-gui.exe
执行Configure：
运行之...
In Matplotlib, what does the argument mean in fig.add_subplot(111)?
... a single integer. For example, "111" means "1x1 grid, first subplot" and "234" means "2x3 grid, 4th subplot".
Alternative form for add_subplot(111) is add_subplot(1, 1, 1).
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