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Mongodb Explain for Aggregation framework
... an explain function for the Aggregation framework in MongoDB? I can't see it in the documentation.
3 Answers
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Geometric Mean: is there a built-in?
...ion involving length(x) is necessary for the cases where x contains non-positive values.
gm_mean = function(x, na.rm=TRUE){
exp(sum(log(x[x > 0]), na.rm=na.rm) / length(x))
}
Thanks to @ben-bolker for noting the na.rm pass-through and @Gregor for making sure it works correctly.
I think some...
Mixing a PHP variable with a string literal
Say I have a variable $test and it's defined as: $test = 'cheese'
4 Answers
4
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What is NSLayoutConstraint “UIView-Encapsulated-Layout-Height” and how should I go about forcing it
I have a UITableView running under iOS 8 and I'm using automatic cell heights from constraints in a storyboard.
17 Answer...
How to check whether dynamically attached event listener exists or not?
Here is my problem: is it possible somehow to check for existence of dynamically attached event listener? Or how can I check the status of the "onclick" (?) property in DOM? I have searched internet just like Stack Overflow for a solution, but no luck. Here is my html:
...
CGContextDrawImage draws image upside down when passed UIImage.CGImage
...the middle of your begin/end CGcontext methods.
This will draw the image with the correct orientation into your current image context - I'm pretty sure this has something to do with the UIImage holding onto knowledge of the orientation while the CGContextDrawImage method gets the underlying raw ima...
What is a callback function?
... completes
A nice way of imagining how a callback function works is that it is a function that is "called at the back" of the function it is passed into.
Maybe a better name would be a "call after" function.
This construct is very useful for asynchronous behaviour where we want an activity to t...
CreateWindow()动态创建一个EditBox - C/C++ - 清泛网 - 专注C/C++及内核技术
CreateWindow()动态创建一个EditBox在Win32代码或MFC代码中动态创建一个EditBox：在OnInitDialog()函数中： 创建EditBox HWND m_wndEdit = CreateWindow(_T("EDI...在Win32代码或MFC代码中动态创建一个EditBox：
在OnInitDialog()函数中：
// 创建Edit...
error: cannot dynamic_cast ‘b’ (of type ‘class Base*’) to type ‘c...
...std;
class Base {
public:
Base() {};
virtual ~Base() {}; // make it polymorphic
};
template<class T>
class Derived: public Base {
T _val;
public:
Derived() {}
Derived(T val): _val(val) {}
T raw() {return _val;}
};
int main()
{
Base * b = new Derived<int>(1);
De...
【解决】Missing FindPython3.cmake - C/C++ - 清泛网移动版 - 专注C++内核技术
...ckage configuration file provided by "Python3"
(requested version 3.6) with any of the following names:
Python3Config.cmake
python3-config.cmake
Add the installation prefix of "Python3" to CMAKE_PREFIX_PATH or set
"Python3_DIR" to a directory containing one of the above files....