Tutorial by Examples: p

The typical example is an abstract shape class, that can then be derived into squares, circles, and other concrete shapes. The parent class: Let's start with the polymorphic class: class Shape { public: virtual ~Shape() = default; virtual double get_surface() const = 0; virtual vo...

Packages are collections of R functions, data, and compiled code in a well-defined format. Public (and private) repositories are used to host collections of R packages. The largest collection of R packages is available from CRAN. Using CRAN A package can be installed from CRAN using following code...

To install package from local source file: install.packages(path_to_source, repos = NULL, type="source") install.packages("~/Downloads/dplyr-master.zip", repos=NULL, type="source") Here, path_to_source is absolute path of local source file. Another command that ...

Here is a full Activity class that places a Marker at the current location, and also moves the camera to the current position. There are a few thing going on in sequence here: Check Location permission Once Location permission is granted, call setMyLocationEnabled(), build the GoogleApiClient, ...

Inspecting system resource usage is an efficient way to narrow down a problem on a live running application. This example is an equivalent of the traditional ps command for containers. docker top 7786807d8084 To filter of format the output, add ps options on the command line: docker top 7786807...

Following the logs is the less intrusive way to debug a live running application. This example reproduces the behavior of the traditional tail -f some-application.log on container 7786807d8084. docker logs --follow --tail 10 7786807d8084 This command basically shows the standard output of the co...

In this example, 2.13.2 is the latest version. We install it via bower, specifying the particular version as ember#2.13.2 and including the save flag to persist it to bower.json. As of writing this post the latest version is 2.13.2. From the command line, in the root of your app's directory, run: ...

Since Ember Data is an Ember CLI add-on we can install it just like any other add-on by using ember install. As of writing this post the latest version is 2.13.1. From the command line, in the root of your app's directory, run: ember install [email protected]

Ember CLI is a normal npm package. To update it we have to uninstall it and then install the version we want. As of writing this post the latest version is 2.13.2. From the command line run: npm uninstall -g ember-cli npm cache clean bower cache clean npm install -g [email protected] To verif...

We will model the process #Load the forecast package library(forecast) #Generate an AR1 process of length n (from Cowpertwait & Meltcalfe) # Set up variables set.seed(1234) n <- 1000 x <- matrix(0,1000,1) w <- rnorm(n) # loop to create x for (t in 2:n) x[t] <- 0.7...

Sometimes you want to do something with the exception you catch (like write to log or print a warning) and let it bubble up to the upper scope to be handled. To do so, you can rethrow any exception you catch: try { ... // some code here } catch (const SomeException& e) { std::cout &l...

A type that conforms to the SequenceType protocol can iterate through it's elements within a closure: collection.forEach { print($0) } The same could also be done with a named parameter: collection.forEach { item in print(item) } *Note: Control flow statements (such as break or continu...

Variables of character type or of a derived type with length parameter may have the length parameter either assumed or deferred. The character variable name character(len=len) name is of length len throughout execution. Conversely the length specifier may be either character(len=*) ... ! Ass...

import pandas as pd import numpy as np np.random.seed(123) x = np.random.standard_normal(4) y = range(4) df = pd.DataFrame({'X':x, 'Y':y}) >>> df X Y 0 -1.085631 0 1 0.997345 1 2 0.282978 2 3 -1.506295 3

You can create a DataFrame from a list of simple tuples, and can even choose the specific elements of the tuples you want to use. Here we will create a DataFrame using all of the data in each tuple except for the last element. import pandas as pd data = [ ('p1', 't1', 1, 2), ('p1', 't2', 3, 4)...

Component code: angular.module('myModule', []).component('myComponent', { bindings: { myValue: '<' }, controller: function(MyService) { this.service = MyService; this.componentMethod = function() { return 2; }; } }); The test: describe('myComponent', f...

val num = 42d Print two decimal places for num using f println(f"$num%2.2f") 42.00 Print num using scientific notation using e println(f"$num%e") 4.200000e+01 Print num in hexadecimal with a println(f"$num%a") 0x1.5p5 Other format strings can be found ...

if ([object respondsToSelector:@selector(someOptionalMethodInProtocol:)]) { [object someOptionalMethodInProtocol:argument]; }

Every authenticated user has a Firebase uid that's unique across all providers and is returned in the result of every authentication method. A good way to store your user's data is to create a node to keep all the users's data and to protect it using your security rules - Database { "use...

You can define scripts that can be executed or are triggered before or after another script. { "scripts": { "pretest": "scripts/pretest.js", "test": "scripts/test.js", "posttest": "scripts/posttest.js" } } ...