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data.table vs dplyr: can one do something well the other can't or does poorly?
...ters. As Grace Hopper would say, Mind your nanoseconds!
3. Syntax
Let's now look at syntax. Hadley commented here:
Data tables are extremely fast but I think their concision makes it harder to learn and code that uses it is harder to read after you have written it ...
I find this remark poi...
Cannot pass null argument when using type hinting
...roblem I have with this is that it changes the definition of the function. Now the parameter is optional - which isn't really what the author intended (although, if he is passing it null, it is implicitly optional).
– crush
Jan 29 '13 at 13:35
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How to delete an item in a list if it exists?
... in iterable if item] if the first argument is None); in Python 3.x, it is now equivalent to (item for item in iterable if function(item)). The subtle difference is that filter used to return a list, now it works like a generator expression - this is OK if you are only iterating over the cleaned lis...
How to convert OutputStream to InputStream?
...a OutputStream and second one, which accepts only InputStream . Do you know how to convert OutputStream to InputStream (not vice versa, I mean really this way) that I will be able to connect these two parts?
...
What is the best way to detect a mobile device?
...ackberry|iemobile|opera mini/i.test(navigator.userAgent.toLowerCase()));
Now $.browser will return "device" for all above devices
Note: $.browser removed on jQuery v1.9.1. But you can use this by using jQuery migration plugin Code
A more thorough version:
var isMobile = false; //initiate as f...
CSS image resize percentage of itself?
... This doesn't resize the image to 50% of it's original size, it's now 50% of the parent of img_wrap..
– Wesley
May 25 '12 at 9:46
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Get form data in ReactJS
...se React's two-way databinding helper mixin to achieve the same thing, but now it's deprecated in favor of setting the value and change handler (as above):
var ExampleForm = React.createClass({
mixins: [React.addons.LinkedStateMixin],
getInitialState: function() {
return {email: '', passwor...
What's the difference between tag and release?
...email to support@github.com or this contact form.
Update:
The GitHub API now allows to manipulate Releases. See the announcement.
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Providing a default value for an Optional in Swift?
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Update
Apple has now added a coalescing operator:
var unwrappedValue = optionalValue ?? defaultValue
The ternary operator is your friend in this case
var unwrappedValue = optionalValue ? optionalValue! : defaultValue
You could also pr...
Optimal number of threads per core
...
I know this question is rather old, but things have evolved since 2009.
There are two things to take into account now: the number of cores, and the number of threads that can run within each core.
With Intel processors, the nu...