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Calculating moving average
... of non-NA values. Here's one way of doing that, incorporating the comment from @Ricardo Cruz:
cx <- c(0, cumsum(ifelse(is.na(x), 0, x)))
cn <- c(0, cumsum(ifelse(is.na(x), 0, 1)))
rx <- cx[(n+1):length(cx)] - cx[1:(length(cx) - n)]
rn <- cn[(n+1):length(cx)] - cn[1:(length(cx) - n)]
rs...
What does “program to interfaces, not implementations” mean?
...r of a program at run-time. It also helps you to write far better programs from the maintenance point of view.
Here's a basic example for you.
public enum Language
{
English, German, Spanish
}
public class SpeakerFactory
{
public static ISpeaker CreateSpeaker(Language language)
{
...
Why do we use $rootScope.$broadcast in AngularJS?
...ent for example)
!!! One thing to not do however is to use $rootScope.$on from a controller. $rootScope is the application, when your controller is destroyed that event listener will still exist, and when your controller will be created again, it will just pile up more event listeners. (So one broa...
not None test in Python [duplicate]
...
From, Programming Recommendations, PEP 8:
Comparisons to singletons like None should always be done with is or is not, never the equality operators.
Also, beware of writing if x when you really mean if x is not None — e.g....
PEP 8, why no spaces around '=' in keyword argument or a default parameter value?
...to have different conventions IMO, because the difference is already clear from context. The former happens within a function call, and the latter needs to stand alone at the current indentation level. IMO, for variable names longer than 5-6 characters (i.e. real life for most), the variant with spa...
What kind of virtual machine is BEAM (the Erlang VM)?
From what I understand a virtual machine falls into two categories either "system virtual machine" or a "process virtual machine". It's kind of fuzzy to me where BEAM lies. Is there another kind of virtual machine I am not aware of?
...
“:” (colon) in C struct - what does it mean? [duplicate]
...r after the colon describes how many bits that field uses. Here is a quote from MSDN describing bit fields:
The constant-expression specifies the width of the field in bits. The
type-specifier for the declarator must be unsigned int, signed int, or
int, and the constant-expression must be a ...
How can I reverse a list in Python?
...bout twice as fast (when reversing a 10k elements list and creating a list from it). I did not test memory consumption though. reverse might be faster though, if you don't need to cast to list afterwards.
– Dakkaron
Aug 23 '16 at 14:01
...
Why is no one using make for Java?
... possible to write something that generated all the necessary dependencies from Java source code, so that make would build classes in the correct order one at a time, this still wouldn't handle cases such as circular dependencies.
The Java compiler can also be more efficient by caching the compiled...
VBA - how to conditionally skip a for loop iteration
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Continue For isn't valid in VBA or VB6.
From this MSDN page it looks to have been introduced into VB.Net in VS 2005./Net 2.
As the others have said there's not really an option other than to use Goto or an Else.
...