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Server Side Programming Articles
Page 1223 of 2109
How to subset rows of an R data frame using grepl function?
The grepl function in R search for matches to argument pattern within each element of a character vector or column of an R data frame. If we want to subset rows of an R data frame using grepl then subsetting with single-square brackets and grepl can be used by accessing the column that contains character values.Example1Consider the below data frame:> x1 y1 z1 df1 df1Output x1 y1 z1 1 A 0.8833979 5 2 B 0.5400075 1 3 C 0.6923827 3 4 B 1.5069186 2 5 B 0.8190962 2 6 B 0.8296171 1 7 B ...
Read MoreHow to find the cumulative sum but restarts it if a value is 1 in R?
Sometimes we want to find the conditional cumulative sums and these conditions can be resetting the cumulative if a particular value occurs. For example, finding the cumulative sum of a variable frame but restarting the sum if 1 occurs. In R, we can do this with the help of with, ave and cumusum function as shown in the below examples.Example1Consider the below data frame:> ID Ratings df1 df1Output ID Ratings 1 1 0 2 2 2 3 3 0 4 4 0 5 5 0 6 6 2 ...
Read MoreHow to add a column in an R data frame with consecutive numbers?
Addition of a column with consecutive might have different objectives such as getting the sequence of numbers, representing serial numbers, representing ids, identification of each row, or a variable. We can use the sequence starting from any number up to the number of rows if we know the number of rows for this purpose.Example1Consider the below data frame:> x1 x2 df1 df1Output x1 x2 1 6.137898 5.203712 2 5.283467 5.057344 3 5.873749 4.907388 4 7.628762 5.012650 5 4.134700 4.988379 6 5.340686 4.684900 7 5.126999 4.821752 8 3.722762 4.974044 9 4.097969 ...
Read MoreHow to find the residual of a glm model in R?
In a linear model, a residual is the difference between the observed value and the fitted value and it is not different for a general linear model. The difference between linear model and the general linear model is that we use a probability distribution to create a general linear model. If we want to find the residual for a general linear model then resid function can be used just like it is used with the linear model.Example1Consider the below data frame:> x1 y1 df1 df1Output x1 y1 1 4 2 2 3 3 3 5 3 4 4 2 5 ...
Read MoreProgram to find nth ugly number in C++
Suppose we have a number n; we have to find the nth ugly number. As we know that the ugly numbers are those numbers, whose prime factors are only 2, 3 and 5. So if we want to find 10th ugly number, the output will be 12, as the first few ugly numbers are 1, 2, 3, 4, 5, 6, 8, 9, 10, 12 and so on.To solve this, we will follow these steps:Define an array v of size(n + 1)if n is same as 1, then:return 1two := 2, three := 3, five := 5twoIdx := 2, threeIdx := 2, fiveIdx := 2for initialize i := 2, when i
Read MoreCount Numbers with N digits which consists of even number of 0's in C++
We are given a number N as input. The goal is to find all N digit numbers that have an even number of 0’s as digits. The number also could have preceding zeros like in case of N=3 numbers included will be 001, 002, 003….010….so on.Let us understand with examples.Input − N=4Output − Count of no. with N digits which consists of even number of 0's are − 7047Explanation − All 4 digits numbers would be like −Smallest will be 0000, then 0011, 0012, 0013, 0014…..Highest will be 9900.Input − N=5Output − Count of no. with N digits which consists ...
Read MoreCount Numbers with N digits which consists of odd number of 0's in C++
We are given a number N as input. The goal is to find all N digit numbers that have an odd number of 0’s as digits. The number also could have preceding zeros like in case of N=3 numbers included will be 000, 011, 012….990.Let us understand with examples.Input − N=3Output − Count of no. with N digits which consists of even number of 0's are − 244Explanation − All 3 digit numbers would be like −Smallest will be 000, then 011, 012, 013, 0014…..Highest will be 990.Input − N=5Output − Count of no. with N digits which consists of ...
Read MoreCount subsets having distinct even numbers in C++
We are given an array of positive integers. The goal is to find the subsets of numbers in an array such that each subset has distinct even numbers in it. All sets with the same elements will be counted as 1. [2, 4, 6] and [6, 2, 4] are the same set.Let us understand with examplesInput − arr[] = {1, 3, 5, 7, 8, 3, 2 };Output −Count of subsets having distinct even numbers are − 3Explanation − Subsets will be − [2], [8], [2, 8]Input − arr[] = {2, 4, 6 };Output −Count of subsets having distinct even numbers ...
Read MoreProgram to count how many numbers should be appended to create all numbers from 1 to k in C++
Suppose we have a list of numbers called nums and another value k. We have to find the minimum number of numbers that we need to insert into nums such that we can make any number from [1, k] using some subset in nums.So, if the input is like nums = [3, 5], k = 6, then the output will be 2, as we have to insert 1, 2, so we can make : 1 = [1], 2 = [2], 3 = [3], 4 = [1, 3], 5 = [5], 6 = [1, 5].To solve this, we will follow these ...
Read MoreCount pairs of numbers from 1 to N with Product divisible by their Sum in C++
We are given a number N. The goal is to find the pairs of numbers from 1 to N such that the product of pairs is equal to the sum of pairs.Let us understand with examples.Input − N=11Output − Count of pairs of no. from 1 to N with Product divisible by their Sum are − 1Explanation − Numbers 3 and 6 have product 18 and their sum 9 fully divides 18.Input − N=30Output − Count of pairs of no. from 1 to N with Product divisible by their Sum are − 12Explanation − Pairs are − (3, 6), (4, ...
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