Programming Articles - Page 907 of 3363

To create stacked bar plot for one categorical variable in an R data frame, we can use ggplot function and geom_bar function of ggplot2 and provide 1 as the X variable inside aes.For Example, if we have a data frame called df that contains a one categorical column say C and one numerical column Num then we can create the stacked bar plot by using the below command −ggplot(df,aes(1,Num,fill=C))+geom_bar(stat="identity")ExampleFollowing snippet creates a sample data frame −x

To find the value in an R data frame column that exist n times, we first need to tabulate the column with factor then extracting the levels of the column after that reading them with as.numeric.Check out the Examples given below to understand how it can be done.Example 1Following snippet creates a sample data frame −x

Memorization is a technique based on dynamic programming which is used to improve the performance of a recursive algorithm by ensuring that the method does not run for the same set of inputs more than once by keeping a record of the results for the provided inputs(stored in an array).Memorization can be achieved by implementing top down approach of the recursive method.Let us understand this scenario with the help of basic Fibonacci example1-D MemorizationWe will be considering a recursive algorithm with only one non constant parameter (only one parameter changes its value) hence this method is called 1-D memorization. The ... Read More

To round matrix values, we can use round function.For Example, if we have a matrix called M and we want to round the value in M to 2 decimal places by using the below command −M

To display numbers with decimal in R data frame column, we can use format function with round function and nsmall argument.For Example, if we have a data frame called df that contains an integer column say X then we can display numbers in X with 2 decimal places by using the below command −df$X

We are given with an integer array of size N(size of multiple 4) and we have to perform Xclusive OR operation on the array such that input[1- 4] resembles utility_arr[1- 4] and the conditions of computing is If arr[1 – 4] = {a1, a2, a3, a4} then q[1 – 4] = {a1 ⊕ a2 ⊕ a3, a1 ⊕ a2 ⊕ a4, a1 ⊕ a3 ⊕ a4, a2 ⊕ a3 ⊕ a4}Let us see various input output scenarios for this -In − int[] input = { 5, 2, 3, 4 };Out − Result after XOR operation 4 3 2 5Explanation −An Exclusive-OR gate's output ... Read More

To change the decimal point of every value in an R data frame column, we can use round function.For Example, if we have a data frame called df that contains a column say X and we want to have each value with 3 decimal places then we can use the below command −df$X

When we find the mean of normal random variable which is created with rnorm(“sample_size”, 10) is not 10 because rnorm will create a random variable hence mean will be changed but as we increase the sample size the mean will become closer to 10.Check out the Examples given below to understand the variation in the Outputs as the sample size increases.ExampleThe variation in the Outputs of mean of normal random variable created by using rnorm as the sample size increases is explained below −mean(rnorm(100, mean=10)) mean(rnorm(100, mean=10)) mean(rnorm(100, mean=10)) mean(rnorm(100, mean=10)) mean(rnorm(100, mean=10)) mean(rnorm(100, mean=10)) mean(rnorm(100, mean=10)) mean(rnorm(1000, mean=10)) mean(rnorm(1000, ... Read More

We are given two integer arrays, one having the elements which are computed and other having split points which are required to split the array for making subset and we have to calculate the sum of each subset in every split and return the maximum subset sum.Let us understand with example:-Input − int arr[] = int arr[] = { 9, 4, 5, 6, 7 } int splitPoints[] = { 0, 2, 3, 1 };Output − Maximum subarray sum after each split [22, 13, 9, 9]Explanation − Here we are breaking the array according to their split points and obtaining the maximum subset sum ... Read More

We are provided with an array and a sum value; the problem statement is to calculate the maximum subset sum which does not exceed the given sum value. We cannot apply the brute force approach here because the structure of the given array is not the same as the divide and conquer approach.Let us see various input output scenarios for this -Let us understand with exampleInput − long arr[] = { 21, 1, 2, 45, 9, 8 } long given_Sum = 12Output −The maximum sum subset having sum less than or equal to the given sum-->12Explanation −The array is split into a set ... Read More