updateState by key can be used to create a stateful DStream based on upcoming data. It requires a function:
object UpdateStateFunctions {
def updateState(current: Seq[Double], previous: Option[StatCounter]) = {
previous.map(s => s.merge(current)).orElse(Some(StatCounter(current)))
}
...
/**
* @param year Full year as int (ex: 2000).
* @param month Month as int, zero-based (ex: 0=January, 11=December).
*/
function daysInMonth(year:int, month:int):int {
return (new Date(year, ++month, 0)).date;
}
function isDaylightSavings(d:Date):Boolean {
var months:uint = 12;
var offset:uint = d.timezoneOffset;
var offsetCheck:Number;
while (months--) {
offsetCheck = (new Date(d.getFullYear(), months, 1)).timezoneOffset;
if (offsetCheck != offset)
ret...
By default, migrations are applied to the same database specified by the db application component. If you want them to be applied to a different database, you may specify the db command-line option like shown below:
yii migrate --db=db2
An abstract class is a class that cannot be instantiated. Abstract classes can define abstract methods, which are methods without any body, only a definition:
abstract class MyAbstractClass {
abstract public function doSomething($a, $b);
}
Abstract classes should be extended by a child cla...
A simple bit-field can be used to describe things that may have a specific number of bits involved.
struct encoderPosition {
unsigned int encoderCounts : 23;
unsigned int encoderTurns : 4;
unsigned int _reserved : 5;
};
In this example we consider an encoder with 23 bits of sin...
SELECT *
FROM
table1,
table2
SELECT
table1.column1,
table1.column2,
table2.column1
FROM
table1,
table2
This is called cross product in SQL it is same as cross product in sets
These statements return the selected columns from multiple tables in one query....
The 0b prefix can be used to represent Binary literals.
Binary literals allow constructing numbers from zeroes and ones, which makes seeing which bits are set in the binary representation of a number much easier. This can be useful for working with binary flags.
The following are equivalent ways o...
AlertDialog.Builder builder = new AlertDialog.Builder(context);
//Set Title
builder.setTitle("Reset...")
//Set Message
.setMessage("Are you sure?")
//Set the icon of the dialog
.setIcon(drawable)
//Set...
Let there be Activity B that can be opened, and can further start more Activities. But, user should not encounter it when navigating back in task activities.
The simplest solution is to set the attribute noHistory to true for that <activity> tag in AndroidManifest.xml:
<activity
a...
Imagine you have the following HTML:
<div>
<label>Name:</label>
John Smith
</div>
And you need to locate the text "John Smith" after the label element.
In this case, you can locate the label element by text and then use .next_sibling property:
from ...
BeautifulSoup has a limited support for CSS selectors, but covers most commonly used ones. Use select() method to find multiple elements and select_one() to find a single element.
Basic example:
from bs4 import BeautifulSoup
data = """
<ul>
<li class="item&quo...
.SD
.SD refers to the subset of the data.table for each group, excluding all columns used in by.
.SD along with lapply can be used to apply any function to multiple columns by group in a data.table
We will continue using the same built-in dataset, mtcars:
mtcars = data.table(mtcars) # Let's not ...
SyncAdapter
/**
* Define a sync adapter for the app.
* <p/>
* <p>This class is instantiated in {@link SyncService}, which also binds SyncAdapter to the system.
* SyncAdapter should only be initialized in SyncService, never anywhere else.
* <p/>
* <p>The system ca...
Sometimes it is appropriate to use an immutable empty collection. The Collections class provides methods to get such collections in an efficient way:
List<String> anEmptyList = Collections.emptyList();
Map<Integer, Date> anEmptyMap = Collections.emptyMap();
Set<Number> anEmptySe...
