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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to return the index of first unique character without inbuilt functions using C#?
Create an empty new array of length 256, traverse through the entire string character by character and increment the value in the new array. At the end traverse the entire array and return the first character that has value 1.Example 1aabccd -→2 1 2 1 → Return the first character which is having count 1. That is b.Example 2using System; namespace ConsoleApplication{ public class Arrays{ public int ReturnIndexOfFirstUniqueCharachter(string s){ int index = -1; int[] arrayValues = new int[256]; for (int i = 0; i ...
Read MoreHow to find the row sums by excluding a column in R data frame?
Suppose we have a numerical column in an R data frame that we do not want to include our analysis due to some characteristics such is similarity or distinction with the rest of the data then we might want to exclude that column from the analysis. One such situation would be finding the row sums by excluding a column. For this purpose, we can use the below steps −First of all, creating a data frame.Finding the row sums with the help of mutate function of dplyr package and setdiff function in base RCreate the data frameLet's create a data frame ...
Read MoreHow to create the combination of rows in two data frames having same columns in R?
To create the combination of rows in two data frames having same columns in R, we can follow the below steps −First of all, create two data frames.Then, combine the rows in the data frames with expand.grid and cbind with do.call.Create the data framesLet's create a data frame as shown below −Class
Read MorePython – Combine list with other list elements
When it is required to combine list with other list elements, a simple iteration and ‘append’ method is used.Below is a demonstration of the same −Examplemy_list_1 = [12, 14, 25, 36, 15] print("The first list is :") print(my_list_1) my_list_2 = [23, 15, 47, 12, 25] print("The second list is :") print(my_list_2) for element in my_list_2 : my_list_1.append(element) print ("The result is :") print(my_list_1)OutputThe first list is : [12, 14, 25, 36, 15] The second list is : [23, 15, 47, 12, 25] The result is : [12, 14, 25, 36, 15, 23, 15, 47, ...
Read MoreHow to replace NAs with non-NA if there is only one non-NA in R data frame based on another column?
If we have only one non-NA value in an R data frame column and a column that is categorical then we might want to replace the NAs with the given non-NA. For this purpose, we can follow the below steps −First of all, creating a data frameThen replacing the NA with non-NA with the help of min function of base R and mutate function of dplyr package.Create the data frameLet's create a data frame as shown below −Grp
Read MoreHow to combine multiple columns into one in R data frame without using column names?
To combine multiple columns into one in R data frame without using column names, we can follow the below steps −First of all, create a data frame.Then, convert the data frame into a single column data frame.Again, convert the data frame into a single column without column names displayed in rows using row.names function.Create the data frameLet's create a data frame as shown below −Examplex
Read MoreWhat are the different ways to find missing numbers in a sorted array without any inbuilt functions using C#?
There are three methods as written below −In the first methodUse the formula n(n+1)/2 that counts the number of elements and then need to subtract from the elements in the array.In the second methodCreate a new array and traverse through the entire array and make the number false whichever is found.In the third methodUse Xor operation. which gives the missing number.Exampleusing System; namespace ConsoleApplication{ public class Arrays{ public int MissingNumber1(int[] arr){ int totalcount = 0; for (int i = 0; i < arr.Length; i++){ ...
Read MorePython – Extract Rear K digits from Numbers
When it is required to extract rear K digits from numbers, a simple list comprehension, the modulo operator and the ‘**’ operator are used.Below is a demonstration of the same −Examplemy_list = [51645, 24567, 36743, 89452, 2122] print("The list is :") print(my_list) K = 3 print("The value of K is ") print(K) my_result = [element % (10 ** K) for element in my_list] print("The result is :") print(my_result)OutputThe list is : [51645, 24567, 36743, 89452, 2122] The value of K is 3 The result is : [645, 567, 743, 452, 122]ExplanationA list is defined and displayed ...
Read MoreHow to test for the difference between two regression coefficients in R?
To test for the difference between two regression coefficients, we can follow the below steps −First of all, creating data frame.Then creating a regression model.After that testing the difference between regression coefficients using LienarHypothesis function of car package.Create the data frameLet's create a data frame as shown below −x1
Read MoreDetermining the User IP Address in Node
Node.js is a completely open source technology that runs on JavaScript runtime environment. When the users want to access a website or link, they connect with the link using their system IP. We can use the dns.lookup() method in Node to find the IP address of the current user.Syntaxdns.lookup(hostname, [options], callback)ParametersThe parameters are described below −hostname − This input parameter consists of the web link which is valid or active.options − Default is 0. It takes input for the IP type, i.e., 4 for Ipv4 and 6 for Ipv6.callback − Handles any error if it occursExample 1Create a file with ...
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