Tutorial by Examples: ti

Installation or Setup using Python

1) scikit learn scikit-learn is a Python module for machine learning built on top of SciPy and distributed under the 3-Clause BSD license. It features various classification, regression and clustering algorithms including support vector machines, random forests, gradient boosting, k-means and DBSCA...

machine-learning • Getting started with machine-learning

Creating a new program using .NET Core

First install the .NET Core SDK by going through the installation instructions for the platform of your choice: Windows OSX Linux Docker After the installation has completed, open a command prompt, or terminal window. Create a new directory with mkdir hello_world and change into the ne...

C# Language • Getting started with C# Language

Using the where statement in a switch

The where statement may be used within a switch case match to add additional criteria required for a positive match. The following example checks not only for the range, but also if the number is odd or even: switch (temperature) { case 0...49 where temperature % 2 == 0: print(&quot...

Swift Language • Switch

Getting the string representation of a Guid

A string representation of a Guid can be obtained by using the built in ToString method string myGuidString = myGuid.ToString(); Depending on your needs you can also format the Guid, by adding a format type argument to the ToString call. var guid = new Guid("7febf16f-651b-43b0-a5e3-0da8da4...

C# Language • Guid

Blocks as Properties

@interface MyObject : MySuperclass @property (copy) void (^blockProperty)(NSString *string); @end When assigning, since self retains blockProperty, block should not contain a strong reference to self. Those mutual strong references are called a "retain cycle" and will prevent the...

Objective-C Language • Blocks

Installation or Setup

Google Apps Script does not require setup or installation. The only requirement is a Google Account. A Gmail account works as well as a Google Apps for Work/Education/Government account. You can create a new Google account by going to accounts.google.com Start your first script by going to script.g...

google-apps-script • Getting started with google-apps-script

Dynamic class creation

Classes can be created dynamically through the use of Class.new. # create a new class dynamically MyClass = Class.new # instantiate an object of type MyClass my_class = MyClass.new In the above example, a new class is created and assigned to the constant MyClass. This class can be instanti...

Ruby Language • Classes

Current Date and Time

R is able to access the current date, time and time zone: Sys.Date() # Returns date as a Date object ## [1] "2016-07-21" Sys.time() # Returns date & time at current locale as a POSIXct object ## [1] "2016-07-21 10:04:39 CDT" as.numeric(Sys...

R Language • Date and Time

Formatting Dates

To format Dates we use the format(date, format="%Y-%m-%d") function with either the POSIXct (given from as.POSIXct()) or POSIXlt (given from as.POSIXlt()) d = as.Date("2016-07-21") # Current Date Time Stamp format(d,"%a") # Abbreviated Weekday ## [1] &qu...

R Language • The Date class

Formatting and printing date-time objects

# test date-time object options(digits.secs = 3) d = as.POSIXct("2016-08-30 14:18:30.58", tz = "UTC") format(d,"%S") # 00-61 Second as integer ## [1] "30" format(d,"%OS") # 00-60.99… Second as fractional ## [1] "30.579" for...

R Language • Date-time classes (POSIXct and POSIXlt)

Parsing strings into date-time objects

The functions for parsing a string into POSIXct and POSIXlt take similar parameters and return a similar-looking result, but there are differences in how that date-time is stored; see "Remarks." as.POSIXct("11:38", # time string format = "...

R Language • Date-time classes (POSIXct and POSIXlt)

Getting Started: Hello world!

Creating an HTML document and enabling knockout.js Create an HTML file and include knockout.js via a <script> tag. <!DOCTYPE html> <html> <head> <title>Hello world! (knockout.js)</title> </head> <body> <script src="https://cdnjs...

knockout.js • Getting started with knockout.js

INSERT multiple rows of data

To insert multiple rows of data in SQL Server 2008 or later: INSERT INTO USERS VALUES (2, 'Michael', 'Blythe'), (3, 'Linda', 'Mitchell'), (4, 'Jillian', 'Carson'), (5, 'Garrett', 'Vargas'); To insert multiple rows of data in earlier versions of SQL Server, use "UNION ALL" like so: ...

Microsoft SQL Server • INSERT INTO

UNIQUEIDENTIFIER

A 16-byte GUID / UUID. DECLARE @GUID UNIQUEIDENTIFIER = NEWID(); SELECT @GUID -- 'E28B3BD9-9174-41A9-8508-899A78A33540' DECLARE @bad_GUID_string VARCHAR(100) = 'E28B3BD9-9174-41A9-8508-899A78A33540_foobarbaz' SELECT @bad_GUID_string, -- 'E28B3BD9-9174-41A9-8508-899A78A33540_foobarbaz' ...

SQL • Data Types

Converting NSArray to NSMutableArray to allow modification

NSArray *myColors = [NSArray arrayWithObjects: @"Red", @"Green", @"Blue", @"Yellow", nil]; // Convert myColors to mutable NSMutableArray *myColorsMutable = [myColors mutableCopy];

Objective-C Language • NSArray

Installation or Setup

See Boost Getting Started. Most of the Boost libraries are header-only, meaning that there's nothing you have to compile or link to. Make sure you are getting the most recent version of Boost: Visit www.boost.org Look for the Current Release download. Currently, this links here. Select the ...

boost • Getting started with boost

Dictionary method changes

In Python 3, many of the dictionary methods are quite different in behaviour from Python 2, and many were removed as well: has_key, iter* and view* are gone. Instead of d.has_key(key), which had been long deprecated, one must now use key in d. In Python 2, dictionary methods keys, values and items ...

Python Language • Incompatibilities moving from Python 2 to Python 3

Checking all the properties in a file

quickCheckAll is a Template Haskell helper which finds all the definitions in the current file whose name begins with prop_ and tests them. {-# LANGUAGE TemplateHaskell #-} import Test.QuickCheck (quickCheckAll) import Data.List (sort) idempotent :: Eq a => (a -> a) -> a -> Bool ...

Haskell Language • QuickCheck

Installation

Installing mongoose is as easy as running the npm command npm install mongoose --save But make sure you have also installed MongoDB for your OS or Have access to a MongoDB database. Connecting to MongoDB database: 1. Import mongoose into the app: import mongoose from 'mongoose'; 2. Specify...

mongoose • Getting started with mongoose

trailing decltype in function templates

C++11 One of constraining function is to use trailing decltype to specify the return type: namespace details { using std::to_string; // this one is constrained on being able to call to_string(T) template <class T> auto convert_to_string(T const& val, int ) ->...

C++ • SFINAE (Substitution Failure Is Not An Error)