Server Side Programming Articles - Page 743 of 2650

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

To create a vertical line using ggplot2, we can use geom_vline function of ggplot2 package and if we want to have a dotted vertical line then linetype will be set to 3 inside the same function. To draw the line, we will have to provide xintercept because the line will start on X-axis.Check out the below example to understand how it works.ExampleFollowing snippet creates a sample data frame −x

Suppose we have a matrix called M that contains three columns and we want to subset row values of M but from different columns that means the subset will not have values only from a single column.Hence, before creating the subset we first need to find the column numbers that can be used for the creation of subset and this can be done with the help of sample function if column numbers are not known. After that we can use cbind function with single square brackets for subsetting.Check out the Examples given below to understand how it can be done.Example ... Read More

To find the row products for each row in an R matrix, we can use rowProds function of matrixStats package.For Example, if we have a matrix called MATRIX then we can find the row products for each row in MATRIX by using the command given below −rowProds(MATRIX)Example 1Following snippet creates a sample matrix −M1

A pie chart is a circular representation of data which is created for either nominal data or ordinal data. The slices in the pie chart depends on the magnitude of the data values. If we want to create a pie chart in base R with then pie function can be used along with labels argument.Check out the Examples given below to understand how it can be done.ExampleTo create a pie chart in base R with labels, use the following command −x