Tutorial by Examples: u

DROP INDEX ix_cars_employee_id ON Cars; We can use command DROP to delete our index. In this example we will DROP the index called ix_cars_employee_id on the table Cars. This deletes the index entirely, and if the index is clustered, will remove any clustering. It cannot be rebuilt without rec...

Factories can be used in conjunction with Inversion of Control (IoC) libraries too. The typical use case for such a factory is when we want to create an object based on parameters that are not known until run-time (such as the current User). In these cases it can be sometimes be difficult (if no...

Enumerating dictionaries allows you to run a block of code on each dictionary key-value pair using the method enumerateKeysAndObjectsUsingBlock:(void (^)(id key, id obj, BOOL *stop))block Example: NSDictionary stockSymbolsDictionary = @{ @"AAPL":...

In [1]: import numpy as np In [2]: import pandas as pd In [3]: df = pd.DataFrame({'A': list('XYZXYZXYZX'), 'B': [1, 2, 1, 3, 1, 2, 3, 3, 1, 2], 'C': [12, 14, 11, 12, 13, 14, 16, 12, 10, 19]}) In [4]: df.groupby('A')['B'].agg({'mean': np.mean, 'standard deviatio...

import pandas.io.sql import pyodbc import pandas as pd Specify the parameters # Parameters server = 'server_name' db = 'database_name' UID = 'user_id' Create the connection # Create the connection conn = pyodbc.connect('DRIVER={SQL Server};SERVER=' + server + ';DATABASE=' + db + '; UID...

Fourier Transform is probably the first lesson in Digital Signal Processing, it's application is everywhere and it is a powerful tool when it comes to analyze data (in all sectors) or signals. Matlab has a set of powerful toolboxes for Fourier Transform. In this example, we will use Fourier Transfor...

If you set opacity on an element it will affect all its child elements. To set an opacity just on the background of an element you will have to use RGBA colors. Following example will have a black background with 0.6 opacity. /* Fallback for web browsers that don't support RGBa */ background-color...

Objective-C mySwitch.backgroundColor = [UIColor yellowColor]; [mySwitch setBackgroundColor: [UIColor yellowColor]]; mySwitch.backgroundColor =[UIColor colorWithRed:255/255.0 green:0/255.0 blue:0/255.0 alpha:1.0]; mySwitch.backgroundColor= [UIColor colorWithWhite: 0.5 alpha: 1.0]; mySwitch.backg...

The bind attribute can also be applied to derived types: geese.h struct Goose { int flock; float buoyancy; } struct Goose goose_c; geese.f90 use, intrinsic :: iso_c_binding, only : c_int, c_float type, bind(C) :: goose_t integer(c_int) :: flock real(c_float) :: buoyancy e...

In attempt to send a response asynchronously from chrome.runtime.onMessage callback we might try this wrong code: chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) { $.ajax({ url: 'https://www.google.com', method: 'GET', success: functio...

Homebrew You can install Node.js using the Homebrew package manager. Start by updating brew: brew update You may need to change permissions or paths. It's best to run this before proceeding: brew doctor Next you can install Node.js by running: brew install node Once Node.js is installe...

Detailed instructions on getting hdfs set up or installed.

Encoding //Create a Base64 Encoded NSString Object NSData *nsdata = [@"iOS Developer Tips encoded in Base64" dataUsingEncoding:NSUTF8StringEncoding]; // Get NSString from NSData object in Base64 NSString *base64Encoded = [nsdata base64EncodedStringWithOptions:0]; // Print the B...

You can find the installers on Node.js download page. Normally, Node.js recommends two versions of Node, the LTS version (long term support) and the current version (latest release). If you are new to Node, just go for the LTS and then click the Macintosh Installer button to download the package. I...

Several values of the same type can be returned by passing an output iterator to the function. This is particularly common for generic functions (like the algorithms of the standard library). Example: template<typename Incrementable, typename OutputIterator> void generate_sequence(Increment...

Mapreduce is a part of Hadoop. So when Apache Hadoop (or any distribution of Hadoop is installed) MR is automatically installed. MapReduce is the data processing framework over HDFS(Hadoop distributed file system). MR jobs maybe written using Java, python, Scala, R, etc.

Null coalescing is a new operator introduced in PHP 7. This operator returns its first operand if it is set and not NULL. Otherwise it will return its second operand. The following example: $name = $_POST['name'] ?? 'nobody'; is equivalent to both: if (isset($_POST['name'])) { $name = $_P...

Foreword Git can work with video game development out of the box. However the main caveat is that versioning large (>5 MB) media files can be a problem over the long term as your commit history bloats - Git simply wasn't originally built for versioning binary files. The great news is that since...

When initializing a Git repository for Unity development, there are a couple of things that need to be done. Unity Ignore Folders Not everything should be versioned in the repository. You can add the template below to your .gitignore file in the root of your repository. Or alternatively, you can c...

Int("123") // Returns 123 of Int type Int("abcd") // Returns nil Int("10") // Returns 10 of Int type Int("10", radix: 2) // Returns 2 of Int type Double("1.5") // Returns 1.5 of Double type Double("abcd") // Returns nil Note that do...