If we want to add two columns of an R data frame and each of them contains missing values then the addition of columns can be done in one of the following ways −Adding both the column values if they are numeric.Returning numeric if one of the columns has missing value.Returning NA if both the columns have missing value.To this we can take help of apply function and ifelse function as shown in the below given examples.Example 1Following snippet creates a sample data frame −x1

We can take the transpose of vectors stored in an R list by using Map function with do.call. For example, if we have a list called LIST that contains say ten vectors then we can transpose these vectors by using the command given below − do.call(Map,c(f=c,LIST))Check out the below examples to understand how it works.Example 1To take transpose of vectors stored in an R list, use the command given below −List1

To subset a matrix based on values in a particular column, we can use single square brackets and provide the row and column values. The column values will be set for the columns that we want to subset and the row value will be set for the values of the column using which we want to subset the matrix.Check out the below example to understand how it works.ExampleFollowing snippet creates a matrix −M

To highlight outliers in a boxplot, we can create the boxplot with the help of Boxplot function of car package by defining the id.method.For example, if we have a vector called V then the boxplot of V with highlighted outliers can be created by using the below given command −Boxplot(~V,id.method="y")Example 1To highlight outliers in a boxplot, use the command given below −library(car) x

To create an exponential distribution plot, we can use curve function.For example, if we want to create a exponential distribution plot for 100 values with rate parameter equal to ½ then we can use the command given below:curve(dexp(x, rate=1/2), xlim=c(1, 50))Check out the below examples to understand how it works.Example 1To create an exponential distribution plot, use the command given below −curve(dexp(x, rate=1/4), xlim=c(1, 50)) OutputIf you execute all the above given snippets as a single program, it generates the following output: −Example 2To create an exponential distribution plot, use the command given below −curve(dexp(x, rate=1/4), xlim=c(1, 20))OutputIf you execute ... Read More

If a string contains more than one character then all of them could be same or different. If we want to check if a string contains only one type of character, then stri_count_fixed function of stringi package will be used with nchar function.Check out the below given examples to understand how it can be done.Example 1Following snippet creates a sample data frame −Countries

To split a vector into smaller vectors of consecutive values, we can use split function with cumsum function.For example, if we have a vector called X that contains some consecutive values then we split X into smaller vectors of consecutive values by using the command given below −split(x,cumsum(c(1,diff(x)!=1)))Example 1Following snippet creates a vector −x1

To find the mean based on single group value in an R data frame, we can use mean function with subsetting through single square brackets.For example, if we have a data frame called df that contains a categorical column say C having three groups Low, Medium, High and a numerical column say Num then mean of Num for Medium group can be found by using the command given below −mean(df$C[df$Num=="Medium"])Example 1Following snippet creates a sample data frame −Group

Instead of filling missing values, we sometimes need to replace the data with missing values. This might be required in situations when missing values are coded with a number or the actual values are not useful or sensible for the data study. Also, we might want to replace the values with something else in the future.Check out the below given examples to understand how we can fill data.table row with missing values.Example 1Following snippet creates a data.table object −library(data.table) x1

To create a vertical line using ggplot2, we can use geom_vline function of ggplot2 package and if we want to have a wide vertical line with different color then lwd and colour argument will be used. The lwd argument will increase the width of the line and obviously colour argument will change the color.Check out the below given example to understand how it works.ExampleFollowing snippet creates a sample data frame −x