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Programming Articles
Page 1178 of 2547
How to create a subset using character column with multiple matches in R?
Subsetting is one of the most important aspects of data analysis. One such situation could be subsetting the character column based on multiple values. For example, if a character column of an R data frame has 5 categories then we might want to extract only 2 or 3 or 4 values then it can be done by using the filter function of dplyr package with str_detect function of stringr package.Consider the below data frame −ExampleGroup
Read MorePrint all possible ways to convert one string into another string in C++
In this problem, we are given two strings str1 and str2. Our task is to create a program to Print all possible ways to convert one string into another string. Problem Description: Here, we need to find all possible ways using which we can convert str1 to str2. While converting, we can perform any of the three operations, Insert RemoveReplaceLet’s take an example to understand the problem, Input: str1 = “kfeod” str2 = “kfcadq”OutputWay1:Insert q, after d. Replace c by e. Replace o by a.Solution ApproachWe will find the minimum number of edits first and then create a DP matrix. Then check if the character ...
Read MoreHow to create a single data frame from data frames stored in a list with row names in R?
If we have multiples data frames of same size stored in a list and we believe that these data frames have similar characteristic then we can create a single data frame. This can be done with the help of do.call. For example, if we have a list defined with the name List containing data frames with equal number of rows with their names then a single data frame can be created do.call(rbind,unname(List)).Exampledf1
Read MoreHow to collapse data frame rows in R by summing using dplyr?
To collapse data frame rows by summing using dplyr package, we can use summarise_all function of dplyr package. For example, if we have a data frame called df that has a categorical column say Group and one numerical column then collapsing of rows by summing can be done by using the command −df%>%group_by(Group)%>%summarise_all(funs(sum))Consider the below data frame −ExampleGroup
Read MoreWrite a program in Go language to find the element with the maximum value in an array
ExamplesA1 = [2, 4, 6, 7, 8, 10, 3, 6, 0, 1]; Maximum number is 10A2 = [12, 14, 16, 17, 18, 110, 13, 16, 10, 11]; Maximum number is 110Approach to solve this problemStep 1: Consider the number at the 0th index as the maximum number, max_num = A[0]Step 2: Compare max_num with every number in the given array, while iterating.Step 3: If a number is greater than max_num, then assign that number to max_num;Step 4: At the end of iteration, return max_num;Programpackage main import "fmt" func findMaxElement(arr []int) int { max_num := arr[0] for i:=0; i max_num ...
Read MoreWrite a Golang program to find the element with the minimum value in an array
ExamplesA1 = [2, 4, 6, 7, 8, 10, 3, 6, 0, 1]; Minimum number is 0;A2 = [12, 14, 16, 17, 18, 110, 13, 16, 10, 11]; Minimum number is 10;Approach to solve this problemStep 1: Consider the number at the 0th index as the minimum number, min_num = A[0].Step 2: Compare min_num with every number in the given array, while iterating.Step 3: If a number is smaller than min_num, then assign that number to min_num.Step 4: At the end of iteration, return min_num;Programpackage main import "fmt" func findMinElement(arr []int) int { min_num := arr[0] for i:=0; i
Read MoreHow to change the legend shape using ggplot2 in R?
By default, the shape of legend is circular but we can change it by using the guides function of ggplot2 package. For example, if we have a data frame with two numerical columns say x and y, and one categorical column Group then the scatterplot between x and y for different color values of categories in categorical column Group having different shape of legends can be created by using the below command −ggplot(df, aes(x, y, color=Group))+geom_point()+guides(colour=guide_legend(override.aes=list(shape=0)))Here, we can change the shape argument value to any value between starting from 0 to 25.Consider the below data frame −Examplex
Read MoreWrite a Golang program to check whether a given number is prime number or not
Definition: A number is that is greater than 2 and divisible only by itself and 1.Examples: Prime numbers are 2, 3, 5, 7, 11, 13, 113, 119, ..., etc.Approach to solve this problemStep 1: Find square root of the given number, sq_root = √numStep 2: If the given number is divisible by a number that belongs to [2, sq_root], then print “Non Prime Number”Step 3: If not divisible by any number, then print “Prime Number”Programpackage main import ( "fmt" "math" ) func checkPrimeNumber(num int) { if num < 2 { fmt.Println("Number must be greater than 2.") return } sq_root := int(math.Sqrt(float64(num))) for i:=2; i
Read MoreHow to convert a super class variable into a sub class type in Java
Inheritance is a relation between two classes where one class inherits the properties of the other class. This relation can be defined using the extends keyword as −public class A extends B{}The class which inherits the properties is known as sub class or, child class and the class whose properties are inherited is super class or, parent class.In inheritance a copy of super class members is created in the sub class object. Therefore, using the sub class object you can access the members of the both classes.Converting a super class reference variable into a sub class typeYou can try to convert ...
Read MoreBirthday Paradox in C++
The birthday paradox is a very famous problem in the section of probability. The problem statement of this problem is stated as, There are several people at a birthday party, some are having the same birthday collision. We need to find the approximate no. of people at a birthday party on the basis of having the same birthday.In the probability we know that the chance of getting ahead is 1/2 same as if we have some coins, the chance of getting 10 heads is 1/100 or 0.001.Let us understand the concept, The chance of two people having the different birthday ...
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