Tutorial by Examples: cv

Public Visibility

Visible to the class, package, and subclass. Let's see an example with the class Test. public class Test{ public int number = 2; public Test(){ } } Now let's try to create an instance of the class. In this example, we can access number because it is public. public class Ot...

Java Language • Visibility (controlling access to members of a class)

Installing a specific version of a package

PM> Install-Package EntityFramework -Version 6.1.2

.NET Framework • NuGet packaging system

Basic semantic versioning

Before publishing a package you have to version it. npm supports semantic versioning, this means there are patch, minor and major releases. For example, if your package is at version 1.2.3 to change version you have to: patch release: npm version patch => 1.2.4 minor release: npm version min...

Node.js • npm

Basic Variable Declaration

Go is a statically typed language, meaning you generally have to declare the type of the variables you are using. // Basic variable declaration. Declares a variable of type specified on the right. // The variable is initialized to the zero value of the respective type. var x int var s string va...

Go • Variables

Basic ViewPager usage with fragments

A ViewPager allows to show multiple fragments in an activity that can be navigated by either fliping left or right. A ViewPager needs to be feed of either Views or Fragments by using a PagerAdapter. There are however two more specific implementations that you will find most useful in case of using ...

Android • ViewPager

Creating a dynamic variable

dynamic foo = 123; Console.WriteLine(foo + 234); // 357 Console.WriteLine(foo.ToUpper()) // RuntimeBinderException, since int doesn't have a ToUpper method foo = "123"; Console.WriteLine(foo + 234); // 123234 Console.WriteLine(foo.ToUpper()): // NOW A STRING

C# Language • Dynamic type

Load and display an image with OpenCV

With this example, we will see how to load a color image from disk and display it using OpenCV's built-in functions. We can use the C/C++, Python or Java bindings to accomplish this. In C++: #include <opencv2/core.hpp> #include <opencv2/highgui.hpp> #include <iostream> usi...

opencv • Getting started with opencv

Basic VectorDrawable

A VectorDrawable should consist of at least one <path> tag defining a shape <vector xmlns:android="http://schemas.android.com/apk/res/android" android:width="24dp" android:height="24dp" android:viewportWidth="24.0" android:viewpor...

Android • VectorDrawable and AnimatedVectorDrawable

Atomic vectors

Atomic vectors (which excludes lists and expressions, which are also vectors) are subset using the [ operator: # create an example vector v1 <- c("a", "b", "c", "d") # select the third element v1[3] ## [1] "c" The [ operator can also tak...

R Language • Subsetting

Automatic Validation

Alamofire.request("https://httpbin.org/get").validate().responseJSON { response in switch response.result { case .success: print("Validation Successful") case .failure(let error): print(error) } }

iOS • Alamofire

Creating A Basic Value Converter

While Value Converters can be comprised of either a toView or fromView method, in the below example we will be creating a basic Value Converter which just uses the toView method which accepts the value being sent to the view as the first argument. to-uppercase.js export class ToUppercaseValueConve...

aurelia • Value Converters

Access individual pixel values with cv::Mat::at()

To access pixel values in an OpenCV cv::Mat object, you first have to know the type of your matrix. The most common types are: CV_8UC1 for 8-bit 1-channel grayscale images; CV_32FC1 for 32-bit floating point 1-channel grayscale images; CV_8UC3 for 8-bit 3-channel color images; and CV_32FC3 ...

opencv • Pixel Access

Basic validation attributes used in ViewModel

Model using System.ComponentModel.DataAnnotations; public class ViewModel { [Required(ErrorMessage="Name is required")] public string Name { get; set; } [StringLength(14, MinimumLength = 14, ErrorMessage = "Invalid Phone Number")] [Required(ErrorMessag...

asp.net-mvc • Data annotations

Get Specific Version of Item

If you need to get a specific language or version of an item, you can use these overloads of GetItem() Sitecore.Context.Database.GetItem("/sitecore/content/Sitecore", Language.Current, new Version(5));

sitecore • Items

Basic View

index.html <html> <head> <title>Angular-UI Router Example</title> <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.4.9/angular.js"></script> <script type="text/java...

angular-ui-router • Getting started with angular-ui-router

Reading cvs file into a pandas data frame when there is no header row

If the file does not contain a header row, File: 1;str_data;12;1.4 3;str_data;22;42.33 4;str_data;2;3.44 2;str_data;43;43.34 7; str_data; 25; 23.32 you can use the keyword names to provide column names: df = pandas.read_csv('data_file.csv', sep=';', index_col=0, ski...

pandas • Pandas IO tools (reading and saving data sets)

Efficient pixel access using cv::Mat::ptr pointer

If efficiency is important, a fast way to iterate over pixels in a cv::Mat object is to use its ptr<T>(int r) method to obtain a pointer to the beginning of row r (0-based index). According to the matrix type, the pointer will have a different template. For CV_8UC1: uchar* ptr = image.ptr&...