Tutorial by Examples: x

Unlike a parallel for-loop (parfor), which takes the iterations of a loop and distributes them among multiple threads, a single program, multiple data (spmd) statement takes a series of commands and distributes them to all the threads, so that each thread performs the command and stores the results....

Using Alternatives Many Linux distributions use the alternatives command for switching between different versions of a command. You can use this for switching between different versions of Java installed on a machine. In a command shell, set $JDK to the pathname of a newly installed JDK; e.g....

Given a DataFrame with MultiIndex columns # build an example DataFrame midx = pd.MultiIndex(levels=[['zero', 'one'], ['x','y']], labels=[[1,1,0,],[1,0,1,]]) df = pd.DataFrame(np.random.randn(2,3), columns=midx) In [2]: df Out[2]: one zero y x ...

Start with a standard DataFrame df = pd.DataFrame(np.random.randn(2,3), columns=['a','b','c']) In [91]: df Out[91]: a b c 0 -0.911752 -1.405419 -0.978419 1 0.603888 -1.187064 -0.035883 Now to change to MultiIndex, create a MultiIndex object and assign it to df....

MultiIndex can also be used to create DataFrames with multilevel columns. Just use the columns keyword in the DataFrame command. midx = pd.MultiIndex(levels=[['zero', 'one'], ['x','y']], labels=[[1,1,0,],[1,0,1,]]) df = pd.DataFrame(np.random.randn(6,4), columns=midx) In [86]: df Out[86]: ...

To check if a key exists in a Map, use the .has() method: map.has(key); Example: const map = new Map([[1, 2], [3, 4]]); console.log(map.has(1)); // true console.log(map.has(2)); // false

A conversion that involves calling an explicit constructor or conversion function can't be done implicitly. We can request that the conversion be done explicitly using static_cast. The meaning is the same as that of a direct initialization, except that the result is a temporary. class C { std:...

There are two basic classes of exact numeric data types - Integer, and Fixed Precision and Scale. Integer Data Types bit tinyint smallint int bigint Integers are numeric values that never contain a fractional portion, and always use a fixed amount of storage. The range and storage sizes o...

float [(n)] real These data types are used to store floating point numbers. Since these types are intended to hold approximate numeric values only, these should not be used in cases where any rounding error is unacceptable. However, if you need to handle very large numbers, or numbers with an ...

This example shows how to render text along an arc. It includes how you can add functionality to the CanvasRenderingContext2D by extending its prototype. This examples is derived from the stackoverflow answer Circular Text. Example rendering Example code The example adds 3 new text renderi...

1. A Simple Complete Example We could use this sample code to upload the files selected by the user every time a new file selection is made. <input type="file" id="file-input" multiple>   var files; var fdata = new FormData(); $("#file-input").on("cha...

Generally execute() command is used for fire and forget calls (without need of analyzing the result) and submit() command is used for analyzing the result of Future object. We should be aware of key difference of Exception Handling mechanisms between these two commands. Exceptions from submit() ar...

C99 Since C99 the C library has a set of safe conversion functions that interpret a string as a number. Their names are of the form strtoX, where X is one of l, ul, d, etc to determine the target type of the conversion double strtod(char const* p, char** endptr); long double strtold(char const* p...

Here is a very simple example to illustrate how to write a NIF. Directory structure: nif_test ├── c_src │   ├── Makefile │   └── nif_test.c ├── rebar.config └── src ├── nif_test.app.src └── nif_test.erl This structure can be easily initialized using Rebar3: $ rebar3 new lib nif_...

var client = new AmazonDynamoDBClient(); // Store item client.PutItem(new PutItemRequest { TableName = "Books", Item = new Dictionary<string, AttributeValue> { { "Title", new AttributeValue { S = "Cryptonomicon" } }, { "...

var client = new AmazonDynamoDBClient(); Table booksTable = Table.LoadTable(client, "Books"); // Store item Document book = new Document(); book["Title"] = "Cryptonomicon"; book["Id"] = 42; book["Authors"] = new List<string> { "Ne...

This example consists of two parts: first, we must define our Book type; second, we use it with DynamoDBContext. [DynamoDBTable("Books")] class Book { [DynamoDBHashKey] public int Id { get; set; } public string Title { get; set; } public List<string> Authors { ...

Starting with Java 8, you can use lambda expressions & predicates. Example: Use a lambda expressions & a predicate to get a certain value from a list. In this example every person will be printed out with the fact if they are 18 and older or not. Person Class: public class Person { p...

Create TexturePostProcessor.cs file anywhere in Assets folder: using UnityEngine; using UnityEditor; public class TexturePostProcessor : AssetPostprocessor { void OnPostprocessTexture(Texture2D texture) { TextureImporter importer = assetImporter as TextureImporter; ...

For expressing the power of 2 (2^n) of integers, one may use a bitshift operation that allows to explicitly specify the n. The syntax is basically: int pow2 = 1<<n; Examples: int twoExp4 = 1<<4; //2^4 int twoExp5 = 1<<5; //2^5 int twoExp6 = 1<<6; //2^6 ... int twoEx...