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What does .SD stand for in data.table in R
.SD looks useful but I do not really know what I am doing with it. What does it stand for? Why is there a preceding period (full stop). What is happening when I use it?
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How do arrays in C# partially implement IList?
...ional, zero-based arrays, as far as the language is concerned, the array really does implement IList<T> too. Section 12.1.2 of the C# specification says so. So whatever the underlying implementation does, the language has to behave as if the type of T[] implements IList<T> as with any ot...
Trying to add adb to PATH variable OSX
.../bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/Libs/android-sdk-mac_x86/tools:/Libs/android-sdk-mac_x86/platform-tools
You're missing the /Users/simon part.
Also note that if you have both .profile and .bash_profile files, only the latter gets executed.
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WebKit issues with event.layerX and event.layerY
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I have disabled all my extensions and I still get these warnings with 1.7.2
– basZero
May 7 '12 at 7:40
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What are paramorphisms?
...foldr c n xs)
para c n [] = n
foldr c n [] = n
Some people call paramorphisms "primitive recursion" by contrast with catamorphisms (foldr) being "iteration".
Where foldr's two parameters are given a recursively computed value for each recursive subobject of the input data (here, that...
What are the use(s) for tags in Go?
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A tag for a field allows you to attach meta-information to the field which can be acquired using reflection. Usually it is used to provide transformation info on how a struct field is encoded to or decoded from another format (or stored/retrie...
How can I determine whether a 2D Point is within a Polygon?
...integers. Many systems use integers for UI painting (pixels are ints after all), but macOS for example uses float for everything. macOS only knows points and a point can translate to one pixel, but depending on monitor resolution, it might translate to something else. On retina screens half a point ...
Query EC2 tags from within instance
...the ec2-api-tools package, but I got nothing but 404's when I tried to install it.
– Edward Falk
Apr 8 '12 at 19:39
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How do you check in python whether a string contains only numbers?
....isdigit():
From the isdigit documentation:
str.isdigit()
Return True if all characters in the string are digits and there is at least one character, False otherwise. Digits include decimal characters and digits that need special handling, such as the compatibility superscript digits. This covers ...
App store link for “rate/review this app”
... Note - the "type=Purple+Software" has to be there and it has to be literally "Purple Software" - it's not the name of your company, it's a codename for iPhone applications :) I wasted an hour before I figured this out...
– Kuba Suder
Oct 24 '11 at 11:27
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