Tutorial by Examples: s

There might be times where you have a data frame and you want to remove all the rows that might contain an NA value, for that the function complete.cases is the best option. We will use the first 6 rows of the airquality dataset to make an example since it already has NAs x <- head(airquality) ...

A constant expression is an expression that yields a primitive type or a String, and whose value can be evaluated at compile time to a literal. The expression must evaluate without throwing an exception, and it must be composed of only the following: Primitive and String literals. Type ca...

ll | grep ^- | awk -F"." '{print $2 "." $3}' | awk -F":" '{print $2}' | awk '{$1=""; print $0}' | cut -c2- | awk -F"." '{print "mkdir ""$1"";mv ""$1"."$2"" ""$1"""}' >...

In Apache Spark while doing shuffle operations like join and cogroup a lot of data gets transferred across network. Now, to control the number of partitions over which shuffle happens can be controlled by configurations given in Spark SQL. That configuration is as follows: spark.sql.shuffle.partiti...

Java expressions are evaluated following the following rules: Operands are evaluated from left to right. The operands of an operator are evaluated before the operator. Operators are evaluated according to operator precedence Argument lists are evaluated from left to right. Simple Example I...

git filter-branch --force --index-filter \ 'git rm --cached --ignore-unmatch PATH-TO-YOUR-FILE-WITH-SENSITIVE-DATA' \ --prune-empty --tag-name-filter cat -- --all Add your file with sensitive data to .gitignore to ensure that you don't accidentally commit it again. echo "YOUR-FILE-WITH-SE...

BFG Repo cleaner is an alternative to git filter-branch. It can be used to remove sensitive data or large files that were committed wrongly like binaries compiled from the source. It is written in Scala. Project website: BFG Repo Cleaner Requirements The Java Runtime Environment (Java 7 or above ...

; IF d0 == 10 GO TO ten, ELSE GO TO other CMP #10,d0 ; compare register contents to immediate value 10 ; instruction affects the zero flag BEQ ten ; branch if zero flag set other: ; do whatever needs to be done for d0 != 10 BRA ...

getFirstName() - returns the context user's first name. getLastName() - returns the context user's last name.

The Z80 has a specific instruction to implement loop counts: DJNZstanding for "decrement B register and jump if not zero". So, B is the register of choice to implement loops on this processor. FOR...NEXT needs to be implemented "backwards", because the register counts down to zer...

Normally the jvm's garbage collection (gc) is transparent to the user (developer/engineer). GC tuning is normally not required unless the user faces a memory leak or has an application that requires large amount of memory - both of which eventually lead to an out-of-memory exception which compels t...

SampleViewModel.vb 'Import classes related to WPF for simplicity Imports System.Collections.ObjectModel Imports System.ComponentModel Public Class SampleViewModel Inherits DependencyObject 'A class acting as a ViewModel must inherit from DependencyObject 'A simple string p...

self.view.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"Background.png"]];

1- Define Your own custom Block typedef void(^myCustomCompletion)(BOOL); 2- Create custom method which takes your custom completion block as a parameter. -(void) customMethodName:(myCustomCompletion) compblock{ //do stuff // check if completion block exist; if we do not check it will ...

BOOL Apple's Objective-C frameworks and most Objective-C/Cocoa code uses BOOL. Use BOOL in objective-C, when dealing with any CoreFoundation APIs Boolean Boolean is an old Carbon keyword , defined as an unsigned char

The sync() method reads and fetched the model data Backbone.sync = function(method, model) { document.write("The state of the model is:"); document.write("<br>"); //The 'method' specifies state of the model document.write(method +...

Flags gulp has very few flags to know about. All other flags are for tasks to use if needed. -v or --version will display the global and local gulp versions --require <module path> will require a module before running the gulpfile. This is useful for transpilers but also has other applica...

Resource loading in Java comprises the following steps: Finding the Class or ClassLoader that will find the resource. Finding the resource. Obtaining the byte stream for the resource. Reading and processing the byte stream. Closing the byte stream. The last three steps are typically accomp...

React components that are pure functions of their props and do not require any internal state can be written as JavaScript functions instead of using the standard class syntax, as: import React from 'react' const HelloWorld = (props) => ( <h1>Hello, {props.name}!</h1> ); ...

To use typescript with react in a node project, you must first have a project directory initialized with npm. To initialize the directory with npm init Installing via npm or yarn You can install React using npm by doing the following: npm install --save react react-dom Facebook released its ow...