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Articles on Trending Technologies
Technical articles with clear explanations and examples
Building an array from a string in JavaScript
We have to write a function that creates an array with elements repeating from the string till the limit is reached.Suppose there is a string ‘aba’ and a limit 5.e.g. string = "string" and limit = 8 will give new arrayconst arr = ["s", "t", "r", "i", "n", “g”, “s”, ”t”]ExampleLet’s write the code for this function −const string = 'Hello'; const limit = 15; const createStringArray = (string, limit) => { const arr = []; for(let i = 0; i < limit; i++){ const index = i % string.length; arr.push(string[index]); ...
Read MoreHow to extract website name from their links in R?
If we have a list of website links and we want to extract the website name from those links then it is a time-consuming task because we would need to copy each name one-by-one. Therefore, it is better to extract them using a function in R and save time. To extract the website name from the website link, we can use suffix_extract function of urltools package. This will extract the host, subdomain, domain and suffix. And it is known that the domain values are the website names.Loading urltools package −library(urltools)Website links stored in a vector −Web_Links
Read MoreHow to find the name of the author of a package in R?
There can be multiple authors of a package in R and we might want to use their name if we are using their package in our publication for research, books, courses or any other type of content. Therefore, it is required to find out all the authors who contributed to a particular package and this can be done by using citation function with package name as shown in the below examples.Examplecitation("ggplot2")To cite ggplot2 in publications, please use −H. Wickham. ggplot2: Elegant Graphics for Data Analysis. Springer-Verlag New York, 2016.A BibTeX entry for LaTeX users is@Book{, author = {Hadley Wickham}, ...
Read MoreHow to create a predictive linear regression line for a range of independent variable in base R?
If we want to create a regression line inside scatterplot then lines function can be used with the linear model function lm but if we want to do it for a particular range of independent variable then this range needs to be defined and passed within the lines function. Check out the below example of linear regression model that considers a range of independent variable for prediction.Consider the below vectors −Examplestrsplit(x6,"[*]")OutputDefining the range of x −Range_of_x
Read MoreHow to convert data.table object into a matrix in R?
A data.table object is very similar to a data frame in R, therefore, converting a data.table object to a matrix is not a difficult job. We just need to use as.matrix function and store the data.table object into a new object that will belong to the matrix, otherwise R will not be able to convert the data.object to a matrix. For example, if we have a data.table object DT then to convert it into a matrix, we should use the below example code −DT_matrix
Read MoreHow does PowerShell Pipeline work – Part 2?
In part-1 we have seen the PowerShell pipeline functionality using the ValueFromPipeline property. There is another cmdlet property known as ValueFromPipelineByPropertyName, which is also useful to know the PowerShell pipeline functionality.Like part-1 command, we can get this property name using the same Get-Command but the filter parameter we will use for the property is ValueFromPipelineByPropertyName.The below example is for the Stop-Service cmdlet.(Get-Command Stop-Service).ParameterSets.parameters | where{$_.ValueFromPipelineByPropertyName -eq 'True'} | Select Name, ParameterTypeOutputName ParameterType ---- ------------- Name System.String[]This means you can use Name property to stop the service. So here we will use Get-Service and its Name property to retrieve services and ...
Read MoreHow does PowerShell Pipeline work – Part 1?
PowerShell is made easier with the Pipeline structure. With the Pipeline structure, we can pass the input of the left side command output or string to the right side of the command as the input. For example, Get-Service | Out-File c:\services.txtIn the above example, we are passing Get-Service output as an object to the Out-File command which is the right side of the Pipeline as the Input. Before going into detail about how the Pipeline works, we need to understand that every command we write produces output and that output is already formatted by the PowerShell using Pipeline.For example, Get-Process ...
Read MoreHow to block ports on the Windows Operating System using PowerShell?
To block the port using PowerShell on the Windows OS, we need to change the firewall settings using the New-NetFirewallRule command.ExampleWe need to block the port 5985 on the computer. The below code will block all TCP Incoming requests on the 5985 port on the local computer.New-NetFirewallRule -DisplayName "Block WINRM HTTP Port" ` -Direction Inbound ` -LocalPort 5985 ` -Protocol TCP ` -Action Block To ...
Read MoreHow to open a port in the Windows Operating System using PowerShell?
To open a port in the Windows Operating system, we need to know a few things. LikeFor which Profile we need to open port (Public, private, or Domain)? - OptionalWhich port do we need to open (port Number)?The direction of the port – Inbound (i.e Incoming requests) or Outbound (i.e. Outgoing requests).Protocol by name (TCP, UDP, ICMPv4, or ICMPv6) or Number (0-255).Once we have all the details we can open the port. In the below example, we need to open a port 5985 (WINRM HTTP) port on the computer which is currently blocked. So we will use the below command.New-NetFirewallRule -DisplayName "Allow WINRM HTTP Port" ` ...
Read MoreHow to change files and folders attributes using PowerShell?
There are multiple files and folders attribute supported by the Windows Operating System. To check which attributes that files and folders support use DOS command attrib /?You can see the attributes listed like Read-Only, Archive, etc. You can set the attribute using PowerShell.For example, we have a file called TestFile.txt and its attribute is ReadOnly and we need to change it to the Archive.PS C:\> (Get-ChildItem C:\Temp\TestFile.txt).Attributes ReadOnlyChange Attribute code −$file = Get-ChildItem C:\Temp\TestFile.txt $file.Attributes = 'Archive'So we have set the attribute to the ‘Archive’ from ‘ReadOnly’ and when you check it, the attribute should be changed.PS C:\> (Get-ChildItem C:\Temp\TestFile.txt).Attributes ...
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