Tutorial by Examples: nd

# Like any other ruby code, require gtk3 after installing from "gem install gtk3" require 'gtk3' # Like in Rails, you import working functions from a higher class, in this case the GTK Window class RubyApp < Gtk::Window # Calling the original method from GTK Window and redefinin...

BufferedImage cat = ImageIO.read(new File("cat.jpg")); //read existing file //modify it Graphics g = cat.createGraphics(); g.setColor(Color.RED); g.drawString("Cat", 10, 10); g.dispose(); //now create a new image BufferedImage cats = new BufferedImage(256, 256, Buffere...

BufferedImage image = new BufferedImage(256, 256, BufferedImage.TYPE_INT_ARGB); //you don't have to use the Graphics object, you can read and set pixel color individually for (int i = 0; i < 256; i++) { for (int j = 0; j < 256; j++) { int alpha = 255; //don't forget this, or ...

Java applets are able to load different resources. But since they are running in the web browser of the client you need to make sure that these resources are accessible. Applets are not able to access client resources as the local file system. If you want to load resources from the same URL the App...

Common Lisp does not have interfaces in the sense that some languages (e.g., Java) do, and there is less need for that type of interface given that Common Lisp supports multiple inheritance and generic functions. However, the same type of patterns can be realized easily using mixin classes. This e...

Let's say we have a table team_person as below: +======+===========+ | team | person | +======+===========+ | A | John | +------+-----------+ | B | Smith | +------+-----------+ | A | Walter | +------+-----------+ | A | Louis | +------+-----------+ | C | ...

To install the software: After the download completes, run the installer. For Windows, the installer executable file has the .exe extension. Double-click the installer file to run it. For Linux platforms, the installer file has the .sh extension. For these platforms, you need to make ...

To run the software: After the download of the platform-independent ZIP file completes, extract it to any folder on your system. Run the executable file located in the netbeans/bin directory. Accept the License Agreement. Click Next. The NetBeans IDE installation starts. Note: If a compatib...

The ROLLUP operator is useful in generating reports that contain subtotals and totals. CUBE generates a result set that shows aggregates for all combinations of values in the selected columns. ROLLUP generates a result set that shows aggregates for a hierarchy of values in the selected col...

The most important thing for speeding up a query on any non-tiny table is to have a suitable index. WHERE a = 12 --> INDEX(a) WHERE a > 12 --> INDEX(a) WHERE a = 12 AND b > 78 --> INDEX(a,b) is more useful than INDEX(b,a) WHERE a > 12 AND b > 78 --> INDEX(a) or INDE...

This example has two parts - some boilerplate steps for adding Castle Windsor to your WCF service, and then a simple, concrete example to show how we configure and use Windsor's container. That makes the example a little bit long. If you already understand using a DI container then you likely only ...

Sometimes we need to perform basic operations like hide/show view based on single value, for that single variable we cannot create model or it is not good practice to create model for that. DataBinding supports basic datatypes to perform those oprations. <layout xmlns:android="http://schema...

First Initialize FirebaseDatabase: FirebaseDatabase database = FirebaseDatabase.getInstance(); Write to your database: // Write a message to the database FirebaseDatabase database = FirebaseDatabase.getInstance(); DatabaseReference myRef = database.getReference("message"); myRef....

NSLog is good, but you can also log by appending to a file instead, using code like: NSFileHandle* fh = [NSFileHandle fileHandleForWritingAtPath:path]; if ( !fh ) { [[NSFileManager defaultManager] createFileAtPath:path contents:nil attributes:nil]; fh = [NSFileHandle fileHandleForWriting...

$ gzip extremelylargefile.txt & $ bg $ disown %1 This allows a long running process to continue once your shell (terminal, ssh, etc) is closed.

There are frequent behavior patterns that can result in a lot of boilerplate code. By declaring a method that takes a Closure as a parameter, you can simplify your program. As an example, it is a common pattern to retrieve a database connection, start a transaction, do work, and then either commit ...

When making a bind of something, for example a date you may want to show it in a specific format without messing around with it in the code. To do this we can use the StringFormat property. Here are some examples: Text="{Binding Path=ReleaseDate, StringFormat=dddd dd MMMM yyyy}" This...

Plenty has been written about Python's GIL. It can sometimes cause confusion when dealing with multi-threaded (not to be confused with multiprocess) applications. Here's an example: import math from threading import Thread def calc_fact(num): math.factorial(num) num = 600000 t = Threa...

In most object oriented languages, allocating memory for an object and initializing it is an atomic operation: // Both allocates memory and calls the constructor MyClass object = new MyClass(); In Objective-C, these are separate operations. The class methods alloc (and its historic sibling allo...

Data frames are R's tabular data structure. They can be written to or read from in a variety of ways. This example illustrates a couple common situations. See the links at the end for other resources. Writing Before making the example data below, make sure you're in a folder you want to write to....