If a class raises a large the number of events, the storage cost of one field per delegate may not be acceptable. The .NET Framework provides event properties for these cases. This way you can use another data structure like EventHandlerList to store event delegates:
public class SampleClass
{
...
[timer invalidate];
timer = nil;
This will stop the timer from firing. Must be called from the thread the timer was created in, see Apple's notes:
You must send this message from the thread on which the timer was installed. If you send this message from another thread, the input source associ...
class Product(models.Model):
name = models.CharField(max_length=20)
price = models.FloatField()
To Get average price of all products:
>>> from django.db.models import Avg, Max, Min, Sum
>>> Product.objects.all().aggregate(Avg('price'))
# {'price__avg': 124.0}
To ...
Subtracting the values of two pointers to an object results in a signed integer *1. So it would be printed using at least the d conversion specifier.
To make sure there is a type being wide enough to hold such a "pointer-difference", since C99 <stddef.h> defines the type ptrdiff_t. ...
Javascript engines first look for variables within the local scope before extending their search to larger scopes. If the variable is an indexed value in an array, or an attribute in an associative array, it will first look for the parent array before it finds the contents.
This has implications wh...
You can evaluate any valid C# code:
int value = await CSharpScript.EvaluateAsync<int>("15 * 89 + 95");
var span = await CSharpScript.EvaluateAsync<TimeSpan>("new DateTime(2016,1,1) - DateTime.Now");
If type is not specified, the result is object:
object value = ...
The CustomEvent API allows developers to create custom events and trigger them on DOM nodes, passing data along the way.
event = new CustomEvent(typeArg, customEventInit);
typeArg - DOMString representing the name of the event.
customEventInit - is optional parameters (that will be passed as e ...
# example data
DT = as.data.table(mtcars, keep.rownames = TRUE)
Editing a column
Use the := operator inside j to create new columns or modify existing ones:
DT[, mpg_sq := mpg^2]
Editing on a subset of rows
Use the i argument to subset to rows "where" edits should be made:
DT[1:...
It is generally not considered 'best practice' to re-purpose the reserved names of Properties or Methods as the name(s) of your own procedures and variables.
Bad Form - While the following is (strictly speaking) legal, working code the re-purposing of the Find method as well as the Row, Column and ...
There is no built-in to iterate over enumeration.
But there are several ways
for enum with only consecutive values:
enum E {
Begin,
E1 = Begin,
E2,
// ..
En,
End
};
for (E e = E::Begin; e != E::End; ++e) {
// Do job with e
}
C++11
with enum clas...
Just as the random forest algorithm may be applied to regression and classification tasks, it can also be extended to survival analysis.
In the example below a survival model is fit and used for prediction, scoring, and performance analysis using the package randomForestSRC from CRAN.
require(rand...
survival is the most commonly used package for survival analysis in R. Using the built-in lung dataset we can get started with Survival Analysis by fitting a regression model with the survreg() function, creating a curve with survfit(), and plotting predicted survival curves by calling the predict m...
Applying css intuitively doesn't produce the desired results because
vertical-align:middle isn't applicable
to block-level elements
margin-top:auto and margin-bottom:auto used values
would compute as zero
margin-top:-50% percentage-based margin values are
calculated relative to the width of ...
The diamond problem, or multiple inheritance, is handled by Scala using Traits, which are similar to Java interfaces. Traits are more flexible than interfaces and can include implemented methods. This makes traits similar to mixins in other languages.
Scala does not support inheritance from multipl...
ExampleScript script = GameObject.FindObjectOfType<ExampleScript>();
GameObject go = script.gameObject;
FindObjectOfType() returns null if none is found.
ProsConsStrongly typedPerformance degrades along the number of gameobjects needed to evaluatePossible to search both single objects...
import flash.utils.*;
var intervalId:uint=setInterval(schroedingerCat,1000);
// execute a function once per second and gather interval ID
trace("Cat's been closed in the box.");
function schroedingerCat():void {
if (Math.random()<0.04) {
clearInterval(intervalId); // ...
