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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to split a string vector that contain strings of equal sizes and have spaces between values then extract only few values in R?
A string vector can contain any value including spaces. Sometimes a string vector is read with some spaces as well and we want to split the vector then extract few values. For example, if a string has “ABC 123” then we might want to extract the number 123 so that we can use it in analysis. If the string vector has strings of equal sizes then it can be easily done with the help of substr function.Examples> x1 x1 [1] "1 00" "1 01" "1 02" "1 03" "1 03" "1 04" > Numeric_Last_two_x1 Numeric_Last_two_x1 [1] "00" "01" "02" "03" ...
Read MoreHow to convert unit of measurements of a value or a vector in R?
There are many units of measurements for a single object or item. For example, weight can be measured in milligrams, grams, kilograms, tons, oz, lbs, etc. Now suppose we have two variables that belong to the same unit of measurement as weight of a coca cola cans and weight of apple juice, if the weights given for both of these variables have different units like one having grams and the other having oz then we might want to convert one of them. This will help us to compare both the variables easily without conflicting the scale of measurements. Therefore, we ...
Read MoreHow to sort a vector in increasing order that contains numbers and characters in R?
A vector can contain numbers, characters or both. The sorting of vectors that contain only numbers or only characters is not very difficult but if a vector contains both of them then it is a little tedious task. In R, we can sort a vector that contains numbers as well as characters with the help of order function but before doing this sorting we must look at the vector very carefully to check if the characters are different for the elements of the vector or not, if they are different then we can’t do this sorting in the manner explained ...
Read MoreHow to create a row at the end an R data frame with column totals?
In data analysis, we often need column totals, especially in situations where we want to perform the analysis in a step by step manner. There are many analytical techniques in which we find the column totals such as ANALYSIS OF VARIANCE, CORRELATION, REGRESSION, etc. To find the column totals, we can use colSums function and use the single square brackets to put these totals as a row in the data frame. Example1 Consider the below data frame − > x1 x2 x3 df1 df1 Output x1 x2 x3 1 1 1 1 2 2 2 2 3 3 3 ...
Read MoreHow do bats use sound to locate their prey?
Bats are mammals which use sound ways to locate their prey. They do so by a scientific technique called 'Echolocation'. This is because they are nocturnal mammals that have weak eyesight. They use their ears more than any other mammal.EcholocationIt is defined as the use of sound waves and echoes to determine the location of objects in space. Bats use this mechanism for finding their food. Just as SONAR (Sound Navigation and Ranging) is used in case of big ships, and tanks, similarly, the emission of sound waves helps bat catch its prey.Bats use ultrasonic waves (20 to 200 kilohertz) ...
Read MoreHow to find and replace the word in a text file using PowerShell?
To search for the word in PowerShell and replace it in the file we will use the string operation. In fact, the Get-Content command in PowerShell is used to read almost any type of file content. In this article, we are considering one text file as shown below.Get-Content C:\Temp\TestFile.txtOutputPS C:\> Get-Content C:\Temp\TestFile.txt # In case of linux, networkInterface names are of the form eth* # In Windows, please use the network full name from Device Manager networkInterfaces: ["Microsoft Hyper-V Network Adapter" ] overrideMetricsUsingScriptFile: false scriptTimeoutInSec: 60 scriptFiles: - osType: windows filePath: monitors/NetworkMonitor/scripts/windows-metrics.bat - osType: unixBase filePath: monitors/NetworkMonitor/scripts/unix-base-metrics.shThe ...
Read MoreWhat is the difference between ErrorActionPreference and ErrorAction cmdlet in PowerShell ?
As we know $ErrorActionPreference and $ErrorAction both have the same functionality and both are used to handle terminating errors by converting Non-Terminating errors to Terminating errors. But when both the variables are used, we need to know which takes precedence.$ErrorActionPreference variable is used at the start of the script while the $erroraction variable is a common parameter and used with the cmdlet. In some cases, we might need the script to be terminated as soon as an error occurs but inside the script, we have some cmdlets which need to be ignored or continued if the error occurs. In that ...
Read MoreHow scriptblock works in PowerShell?
Scriptblock is a set of commands which can be executed together when they are invoked. In PowerShell, generally, we write individual commands. Scriptblock can be written with two curly brackets.Example$sb = {Get-Process powershell; Get-Service W32Time}Here we have written two commands under scriptblock. If you directly run this command, scriptblock treats them as a string.PS C:\> $sb Get-Process powershell; Get-Service W32TimeTo run the commands inside the scritblock, use Invoke-Command with the -Scriptblock parameter.Invoke-Command -ScriptBlock $sbOutputHandles NPM(K) PM(K) WS(K) CPU(s) Id SI ProcessName ------- ------ ----- ----- ------ -- -- ...
Read MoreHow to Copy files or Folder without overwriting existing files?
To copy files/folders on the remote path without overwriting the existing files/folders, you can use multiple cmdlets like Copy-Item, Robocoy, and Xcopy, etc. As Copy-Item is a standard cmdlet, we will check if it's supported parameters can prevent overwriting.If Copy-Item doesn’t work then we will check its alternate command. Copy-Item simply overwrites the files and folders on the destination path and the copies newer files.For example, To copy files from the source folder C:\Test1 to the destination folder C:\Test2 below command is used and it simply overwrites the file without asking.ExampleCopy-Item C:\Test1\* C:\Test2 -Recurse -VerboseOutputPS C:\Temp> Copy-Item C:\Test1\* C:\Test2 -Recurse ...
Read MoreHow to run PowerShell commands in Background?
To run commands in the background in the PowerShell, you need to use Background job cmdlets. Background job means running commands/job in the background without occupying the console.Start-Job is one of the job scheduler cmdlets for PowerShell which runs PowerShell commands in the background without interacting with the current user session as a Job so that users can work in the PowerShell console without losing the control of the console while the command is running in the background.When PowerShell's job starts using Start-Job, a job returns the object immediately even if the job takes an extended time.Start-Job is designed to ...
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