Tutorial by Examples: io

If A is a complex and quadratic matrix there exists a unitary Q such that Q*AQ = T = D + N with D being the diagonal matrix consisting of the eigenvalues and N being strictly upper tridiagonal. A = [3 6 1 23 13 1 0 3 4]; T = schur(A); We also display the runtime of schur dependent on ...

The purpose of this documentation is to use a scanner without any user interface. A common use is to upload a PDF scanned file directly to Google Drive or Dropbox just by pressing scanner-buttons. scanbd permits to trigger actions from the scanner buttons, it uses sane. What make things a little b...

To get data from testcollection collection in testdb database where name=dev import org.bson.Document; import com.mongodb.BasicDBObject; import com.mongodb.MongoClient; import com.mongodb.ServerAddress; import com.mongodb.client.MongoCollection; import com.mongodb.client.MongoCursor; import c...

File.Move In order to move a file from one location to another, one simple line of code can achieve this: File.Move(@"C:\TemporaryFile.txt", @"C:\TemporaryFiles\TemporaryFile.txt"); However, there are many things that could go wrong with this simple operation. For instance, wh...

The leader key could be used as a way to create a mapping with a key-binding that can be overridden by the end user. The leader is the \ key by default. In order to override it, the end-user would have to execute :let g:mapleader='somekey(s)' before defining the mapping. In a typical scenario, the...

wxPython Classic is a Python 2 build of the wxPython library. Generation of the python bindings require a large number of manual interventions and the documentation is simply the wxWidgets documentation which contains some annotations on wxPython mechanisms as such there is normally a delay of weeks...

@Test annotation can be applied to any class or method. This annotation marks a class or a method as part of the test. @Test at method level - mark annotated method as test method @Test at class level The effect of a class level @Test annotation is to make all the public methods of the class ...

First why we should use depedency injection in our code ? We want to decouple other components from other classes in our program. For example we have class AnimalController which have code like this : public class AnimalController() { private SantaAndHisReindeer _SantaAndHisReindeer = new San...

Let's say that you have exam scores for several exams and you want to divide them into quartiles per exam. -- Setup data: declare @values table(Id int identity(1,1) primary key, [Value] float, ExamId int) insert into @values ([Value], ExamId) values (65, 1), (40, 1), (99, 1), (100, 1), (90, 1), ...

This topic demonstrates how to use functions like withColumn, lead, lag, Level etc using Spark. Spark dataframe is an sql abstract layer on spark core functionalities. This enable user to write SQL on distributed data. Spark SQL supports hetrogenous file formats including JSON, XML, CSV , TSV etc. ...

public static Expression<Func<T, bool>> GetExpression<T>(IList<QueryFilter> filters) { Expression exp = null; // Represents a named parameter expression. {parm => parm.Name.Equals()}, it is the param part // To create a ParameterExpression need the ty...

For one filter: Here is where the query is created, it receives a expression parameter and a filter. private static Expression GetExpression<T>(ParameterExpression param, QueryFilter queryFilter) { // Represents accessing a field or property, so here we are accessing for example: ...

ConstantExpression must be the same type of the MemberExpression. The value in this example is a string, which is converted before creating the ConstantExpression instance. private static ConstantExpression GetConstant(Type type, string value) { // Discover the type, convert it, and create Co...

In this very first example, a basic serial write operation is started from an Arduino device. void setup() { // put your setup code here, to run once: Serial.begin(9600); } void loop() { // put your main code here, to run repeatedly: Serial.println("Hello World!"); dela...

If you want to append a series of values [1,2] to the column of dataframe df, you will get NaNs: import pandas as pd series=pd.Series([1,2]) df=pd.DataFrame(index=[3,4]) df['col']=series df col 3 NaN 4 NaN because setting a new column automatically aligns the data by the inde...

The latest JVMs supports Garbage First GC ( G1 GC) and consists of set of regions which accumulate to make young and old generation. The JVM will have approximately 2048 reagions and set heap region size accordingly from 1 MB to 32 MB and power of 2 bounds. This is important parameter which decide ...

Luminus is a Clojure micro-framework based on a set of lightweight libraries. It aims to provide a robust, scalable, and easy to use platform. With Luminus you can focus on developing your app the way you want without any distractions. It also has very good documentation that covers some of the majo...

Scenario: You need to select an implementation of address validation when a sales order is submitted, and the validator is determined by the country to which the order is shipping. The factory needs to inspect some value passed as an argument to select the correct implementation. First, write an in...

Example of map: Promise.resolve([ 1, 2, 3 ]).map(el => { return Promise.resolve(el * el) // return some async operation in real world }) Example of filter: Promise.resolve([ 1, 2, 3 ]).filter(el => { return Promise.resolve(el % 2 === 0) // return some async operation in real world...

Unlike var, const/let are bound to lexical scope rather than function scope. { var x = 1 // will escape the scope let y = 2 // bound to lexical scope const z = 3 // bound to lexical scope, constant } console.log(x) // 1 console.log(y) // ReferenceError: y is not defined console.log(z...