Programming Articles - Page 918 of 3366

To create confusion matrix for a rpart model, we first need to find the predicted values then the table of predicted values and the response variable in the original data can be created, which will be the confusion matrix for the model.For Example, if we have a vector of predicted values say P and original values in data frame df$O then the confusion matrix can be created by using the following command −table(P, df$O)Check out the below Examples to understand how it can be done.Example 1Following snippet creates a sample data frame −Dep_Var1Read More

To create bar plot using ggplot2 with structure data, we need to set the stat argument of geom_bar function to identity. This is same for the regular data frame.For example, if we have a structured data frame called df that contains a column X for categories and a numerical column say Y for frequency then we can the bar plot for this data by using the below given command −ggplot(df,aes(X,Y))+geom_bar(stat="identity")ExampleFollowing snippet creates a sample data frame −df

To find the product of vector elements in pairs moving forward, we can use prod function along with combn function.For Example, if we have a vector called V and we want to find the product of elements of V in pairs moving forward then we can use the following command −combn(V,2,prod)Example 1Following snippet creates a sample data frame −x1

To display data frame name in ggplot2 graph title, we can use ggtitle function and pass the name of the data frame.For example, if we have a data frame called df that contains two columns say x and y and we can create a point chart between x and y then the plot with data frame name as title can be created by using the below mentioned command −ggplot(df,aes(x,y))+geom_point()+ggtitle("df")ExampleFollowing snippet creates a sample data frame −x

To create a colored frame for ggplot2 graph, we can use theme function and set the plot.background argument to different color for rectangular element.For example, if we have a data frame called df that contains two columns say X and Y then we can create point chart between X and Y with blue colored frame of the plot using the below mentioned command −ggplot(df,aes(X,Y))+geom_point()+theme(plot.background=element_rect(colour="blue",size=3))ExampleFollowing snippet creates a sample data frame −x

We are given a string Str as input. The goal is to find if the input string is a palindrome word or not using a recursive function. Palindrome strings are those strings that when read from front or end form the same word. The strings of length 0 are considered as palindromes. Reversing the palindromes character wise forms, the same string as the original.Examples of palindromes are:- madam, abcba, malayalam etcExamplesInput − Str = “malayalam”Output − Input string is palindrome.Explanation −Str[ 0 to 8 ] = malayalamReverse Str [ 8 to 0 ] = malayalamBoth strings are same.Input − Str = “tutorial”Output − Input string ... Read More

To add title to regression model using stargazer, we can use title argument inside stargazer function.For example, if we have a model called Reg_Model with Output as text then the title to this model using stargazer can be added by using the below mentioned command −stargazer(Reg_Model,type="text",title="Regression Model between x and y")Example 1Following snippet creates a sample data frame −x

To delete a row from an R data frame if any value in the row is greater than n can be done by using the subsetting with single square brackets and negation operator. We will subset the values that are greater than n and then take the negation of the subset as shown in the below given examples.Example 1Following snippet creates a sample data frame −x1

To check if any value in an R vector is greater than or less than a certain value, we can use any function.For Example, if we have a vector called V and we want to check if any value in V is greater than 100 then we can use the command given below −any(V>100)Similarly, we can check if any value is less than 100 by using the command as follows −any(V

Bubble Sort is one of the simplest sorting algorithms used to sort data by comparing the adjacent elements. All the elements are compared in phases. The first phase places the largest value at the end, the second phase places the second largest element at the second last position and so on till the complete list is sorted.Bubble Sort Algorithmint arr[5]= { 5, 4, 2, 1, 3 };int i, j ;Traverse from index i=0 to iarr[j] swap arr[i] with arr[j]EndRecursive Bubble SortIf array length is 1 then returnTraverse array once and fix largest element at the endRecursively perform step 2 for ... Read More