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Pass a data.frame column name to a function
I'm trying to write a function to accept a data.frame ( x ) and a column from it. The function performs some calculations on x and later returns another data.frame. I'm stuck on the best-practices method to pass the column name to the function.
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在 App Inventor 2 中使用图像 · App Inventor 2 中文网
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What are copy elision and return value optimization?
...on. Because if we can't, it would severely affect the way we implement our functions in modern C++ (RVO vs std::move). During watching some of the CppCon 2014 videos, i really got the impression that all modern compilers always do RVO. Furthermore, I've read somewhere that also without any optimizat...
How do I return multiple values from a function in C?
If I have a function that produces a result int and a result string , how do I return them both from a function?
8 Answe...
Create aar file in Android Studio
... answered Oct 16 '16 at 18:58
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A numeric string as array key in PHP
...as "08").
Addendum
Because of the comments below, I thought it would be fun to point out that the behaviour is similar but not identical to JavaScript object keys.
foo = { '10' : 'bar' };
foo['10']; // "bar"
foo[10]; // "bar"
foo[012]; // "bar"
foo['012']; // undefined!
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Difference between == and ===
...this your custom class needs to conform Equatable protocol and it's static func == (lhs:, rhs:) -> Bool function
Let's look at example:
class Person : Equatable {
let ssn: Int
let name: String
init(ssn: Int, name: String) {
self.ssn = ssn
self.name = name
}
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Your build failed due to an error in the AAPT stage, not because of an...
...文导致的，换成英文的就ok，这个问题先记录下来，后续fun23.cn平台可以解决。
----------------以下是参考资料-----------
需要注意的事项：该项目已超过 30MB 的最大大小该项目已超出建议的最大 10 个屏幕该项目有一个包含过多文...
How to read data when some numbers contain commas as thousand separator?
...tomatically. First create a new class definition, then create a conversion function and set it as an "as" method using the setAs function like so:
setClass("num.with.commas")
setAs("character", "num.with.commas",
function(from) as.numeric(gsub(",", "", from) ) )
Then run read.csv like:
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Why does PHP consider 0 to be equal to a string?
...r, which will check the type and will not implicitly typecast.
P.S: a PHP fun fact: a == b does not imply that b == a. Take your example and reverse it: if ("e" == $item['price']) will never actually be fulfilled provided that $item['price'] is always an integer.
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