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Creating an R dataframe row-by-row
...ke to construct a dataframe row-by-row in R. I've done some searching, and all I came up with is the suggestion to create an empty list, keep a list index scalar, then each time add to the list a single-row dataframe and advance the list index by one. Finally, do.call(rbind,) on the list.
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Variable declaration in a C# switch statement [duplicate]
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I believe it has to do with the overall scope of the variable, it is a block level scope that is defined at the switch level.
Personally if you are setting a value to something inside a switch in your example for it to really be of any benefit, you would want ...
Reloading module giving NameError: name 'reload' is not defined
...ange class definitions, existing objects will still have the old type. Finally, some modules run code at import time that isn't designed to run twice. So it is better to avoid reloading, but frequently very convenient.
– Evan
Jul 10 '17 at 20:03
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Android DialogFragment vs Dialog
...simple AlertDialog with Yes/No confirmation buttons. Not very much code at all.
With regards handling events in your fragment there would be various ways of doing it but I simply define a message Handler in my Fragment, pass it into the DialogFragment via its constructor and then pass messages back...
Are “elseif” and “else if” completely synonymous?
...tom line is that both would result in exactly the same behavior.
Essentially, they will behave the same, but else if is technically equivalent to a nested structure like so:
if (first_condition)
{
}
else
{
if (second_condition)
{
}
}
The manual also notes:
Note that elseif and els...
将 App Inventor 2 项目连接到外部传感器 · App Inventor 2 中文网
...this effort was to extend AppInventor’s toolset into the physical space, allowing users to easily interface with external sensors, actuators, and other hardware.
The MOIO board[1] is a low-cost, programmable microcontroller and can provide input/output functionality for a wide range of applicatio...
Use of class definitions inside a method in Java
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This is called a local class.
2 is the easy one: yes, a class file will be generated.
1 and 3 are kind of the same question. You would use a local class where you never need to instantiate one or know about implementation details a...
Specify multiple attribute selectors in CSS
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Simple input[name=Sex][value=M] would do pretty nice. And it's actually well-described in the standard doc:
Multiple attribute selectors can be used to refer to several
attributes of an element, or even several times to the same attribute.
Here, the selector matches all SPAN eleme...
Intelligent point label placement in R
...implement INTELLIGENT label placement in R plot? I tried some but they are all problematic - many labels are overlaping either each other or other points (or other objects in the plot, but I see that this is much harder to handle).
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Throwing exceptions from constructors
...ody who creates the object of mutex has to remember that init() has to be called. I feel it goes against the RAII principle.
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