With the rgdal package it is possible to import and export shapfiles with R.
The function readOGR can be used to imports shapfiles. If you want to import a file from e.g. ArcGIS the first argument dsn is the path to the folder which contains the shapefile. layer is the name of the shapefile without...
The packages foreign and haven can be used to import and export files from a variety of other statistical packages like Stata, SPSS and SAS and related software. There is a read function for each of the supported data types to import the files.
# loading the packages
library(foreign)
library(have...
The class we are going to test is:
public class Service {
private Collaborator collaborator;
public Service(Collaborator collaborator) {
this.collaborator = collaborator;
}
public String performService(String input) {
return collaborator.transformStri...
The class we are going to test is:
public class Service{
private Collaborator collaborator;
public Service(Collaborator collaborator){
this.collaborator = collaborator;
}
public String performService(String input){
return collaborator.transformS...
Enumerable is the most popular module in Ruby. Its purpose is to provide you with iterable methods like map, select, reduce, etc. Classes that use Enumerable include Array, Hash, Range.
To use it, you have to include Enumerable and implement each.
class NaturalNumbers
include Enumerable
de...
The core concepts of RxJava are its Observables and Subscribers. An Observable emits objects, while a Subscriber consumes them.
Observable
Observable is a class that implements the reactive design pattern. These Observables provide methods that allow consumers to subscribe to event changes. The ev...
DELETE FROM `table_name` WHERE `field_one` = 'value_one'
This will delete all rows from the table where the contents of the field_one for that row match 'value_one'
The WHERE clause works in the same way as a select, so things like >, <, <> or LIKE can be used.
Notice: It is necessa...
DELETE FROM `table_name` WHERE `field_one` = 'value_one' LIMIT 1
This works in the same way as the 'Delete with Where clause' example, but it will stop the deletion once the limited number of rows have been removed.
If you are limiting rows for deletion like this, be aware that it will delete th...
CommandDescription<C-w>Delete word before cursor<C-t>Indent current line with by one shiftwidth<C-d>Unindent current line with by one shiftwidth<C-f>reindent the line, (move cursor to auto indent position)<C-a>Insert previously inserted text<C-e>Insert the charact...
Privileges
The CREATE VIEW statement requires the CREATE VIEW privilege for the view, and some privilege for each column selected by the SELECT statement. For columns used elsewhere in the SELECT statement, you must have the SELECT privilege. If the OR REPLACE clause is present, you must also have ...
Statement-level parallel hints are the easiest:
SELECT /*+ PARALLEL(8) */ first_name, last_name FROM employee emp;
Object-level parallel hints give more control but are more prone to errors; developers often forget to use the alias instead of the object name, or they forget to include some objec...
4.0.3
Using a CustomTabsIntent, it is now possible to configure Chrome custom tabs in order to customize key UI components in the browser that is opened from your app.
This is a good alternative to using a WebView for some cases. It allows loading of a web page with an Intent, with the added abil...
In C#, there are two different kinds of equality: reference equality and value equality. Value equality is the commonly understood meaning of equality: it means that two objects contain the same values. For example, two integers with the value of 2 have value equality. Reference equality means that ...
There are few approaches available there:
You can subscribe for keyboard appearance events notifications and change offset manually:
//Swift 2.0+
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(YourVCClas...
Common usage of lock is a critical section.
In the following example ReserveRoom is supposed to be called from different threads. Synchronization with lock is the simplest way to prevent race condition here. Method body is surrounded with lock which ensures that two or more threads cannot execute i...
Private inheritance is useful when it is required to restrict the public interface of the class:
class A {
public:
int move();
int turn();
};
class B : private A {
public:
using A::turn;
};
B b;
b.move(); // compile error
b.turn(); // OK
This approach efficiently pr...
