Server Side Programming Articles - Page 720 of 2650

To test if strings stored in a vector are present in an R list or not, we can use mapply function. For example, if we have a vector of strings say V and a list called LIST then we can check whether elements in V are present in LIST by using the following command − mapply(`%in%`,V,LIST)Example 1Following snippet creates a vector and list −x

To find the frequency of successive occurrences less than a threshold value in an R data frame column, we can use rle function along with sum function.Check out the below given examples to understand how it can be done.Example 1Following snippet creates a sample data frame −x

In R, the divisibility of a number by a certain number can be found by using the modulus operator %%. If we want to check the divisibility of a set of numbers by a certain number then for loop will be used.Check out the below given examples to understand how it can be done.Example 1To check which numbers between 1 and 100 are divisible by 10, use the following code −for(x in 1:100){    + if(x%%10==0){          + print(x)    + } + }If you execute the above given code, it generates the following output −[1]  10 ... Read More

Practically, the scatterplots are well visualized on white background just like on white paper. If we want to create a scatterplot with white background and without gridlines using ggplot2 then we can apply classic theme to the plot.Check out the below given example to understand how it can be done.ExampleFollowing snippet creates a sample data frame −x

If we have comma separated values that contains duplicate and unique values then we might want to find the number of unique values within each comma separated value. To find the unique values in comma separated strings stored in an R data frame column, we can use stri_extract_all_regex function of stringi package along with sapply function.Check out the below examples to understand how it can be done.Example 1Following snippet creates a sample data frame −x

If we have a data set that contains missing values at alternate places for each column then we might want to combine the columns by excluding those missing values, this will reduce the data set and the analysis is likely to become easier.For this purpose, we can use na.exclude function along with apply function as shown in the below given examples.Example 1Following snippet creates a sample data frame −x1

To create a colored box for base R plot, we can use box function with col argument where we can pass the color other than black because black is the default color.We first need to create the plot using plot function and then box function will be used as shown in the below given example.ExampleTo create a colored box for base R plot, use the following code −plot(1:5) box(lwd=5, col="blue")OutputIf you execute the above given code, it generates the following output −To create a colored box for base R plot, use the following code −plot(1:5) box(lwd=10, col="red")OutputIf you execute the ... Read More

If we know the total number of rows we want in our matrix and the number of columns then we can use matrix function to create a matrix by filling the data with predefined values. These values must be equal to the multiplication of number of rows and columns.Check out the below given examples to understand how it works.Example 1Following snippet creates a matrix in R by filling the data with predefined values in loop −n=20 k=2 data=rpois(n*k, 5) M1=matrix(data, nrow=n, ncol=k) M1If you execute the above given snippet, it generates the following output −     [, 1] [, 2] ... Read More

The autocorrelation plot or ACF plot is a display of serial correlation in data that changes over time. The ACF plot can be easily created by using acf function.For example, if we have a vector called V then we can create its autocorrelation plot by using the command given below −acf(V)Check out the below examples to understand how it can be done.Example 1To create ACF plot in R, use the code given below −x

If we have a matrix that contains character columns and we want to convert a single column to numeric then we first need to convert the matrix into a data frame using as.data.frame function after that as.numeric function can be used to change the particular column to numeric type as shown in the below examples.Example 1Following snippet creates a matrix −M1