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What's the difference between lapply and do.call?
I'm learning R recently and confused by two function: lapply and do.call . It seems that they're just similar to map function in Lisp. But why are there two functions with such a different name? Why doesn't R just use a function called map ?
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What are the differences between vector and list data types in R?
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Technically lists are vectors, although very few would use that term. "list" is one of several modes, with others being "logical", "character", "numeric", "integer". What you are calling vectors are "atomic vectors" in strict R parl...
What is the equivalent of “none” in django templates?
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None, False and True all are available within template tags and filters. None, False, the empty string ('', "", """""") and empty lists/tuples all evaluate to False when evaluated by if, so you can easily do
{% if profile.user.first_name == None...
Validate that a string is a positive integer
...nclude 0, even though 0 is not positive. I include notes if you want to disallow 0.
Based on Parsing
If you want it to be a normalized decimal integer string over a reasonable range of values, you can do this:
function isNormalInteger(str) {
var n = Math.floor(Number(str));
return n !== I...
What is the difference between procedural programming and functional programming? [closed]
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A functional language (ideally) allows you to write a mathematical function, i.e. a function that takes n arguments and returns a value. If the program is executed, this function is logically evaluated as needed.1
A procedural language, on the other ...
HTML5 Number Input - Always show 2 decimal places
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You can't really, but you a halfway step might be:
<input type='number' step='0.01' value='0.00' placeholder='0.00' />
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Why do C++ libraries and frameworks never use smart pointers?
... their implementations.
But because of the lack of standard ABI, you generally cannot pass these objects safely across module boundaries. A GCC shared_ptr is probably different from an MSVC shared_ptr, which too can differ from an Intel shared_ptr. Even with the same compiler, these classes are not...
href=“tel:” and mobile numbers
...ou often find that the first digit of a telephone number is dropped when dialling internationally, even when using international prefixing to dial within the same country.
So as per the trunk prefix for Germany drop the 0 and add the +49 for Germany's international calling code (for example) giving...
RegEx: Grabbing values between quotation marks
...gt;>> string = '"Foo Bar" "Another Value"'
>>> print re.findall(r'"(.*?)"', string)
['Foo Bar', 'Another Value']
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Securing my REST API with OAuth while still allowing authentication via third party OAuth providers
...web site by supplying some credential such as a username+password. OpenID allows this to be displaced by having the user authenticate to another service, which then asserts the user's identity to your web site on the user's behalf. Your site trusts the third party service (the OpenID Provider) and...