Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
To create sequential index value for binary column assigning 0 to FALSE values in R data frame, we can follow the below steps −First of all, create a data frame with binary column.Then, use rle function along with sequence and lengths function to create sequential index column.ExampleCreate the data frameLet’s create a data frame as shown below −x
To convert first letter of multiple string columns into capital in data.table object in R, we can follow the below steps −First of all, create a data.table object with string columns.Then, use sub function along with mutate_each function of dplyr package to convert first letter into capital in string columns.ExampleCreate the data.table objectLet’s create a data.table object as shown below −library(data.table) Names
To generate a repeated values vector with each value in output selected randomly in R, we can use replicate function. The replicate function will repeat the vector values up to the number of times we want and each value will be randomly selected. To understand how it works, check out the below examples.Example 1Using replicate function to create a vector of exponential random variable of size 10 −x1
To change the background color of base R plot region, we can follow the below steps −First of all, create a plot in base R to understand the difference.Then, use par function with bg argument where you can put color name and then create the same plot.ExampleCreate the plotLet’s create a barplot in base R as shown below −x
To convert values greater than a threshold into 1 in data.table object in R data frame, we can follow the below steps −First of all, create a data.table object.Then, use ifelse function to convert values greater than a threshold into 1.ExampleCreate the data.table objectLet’s create a data.table object as shown below −library(data.table) x
To find the percent of NAs in each row of a data.table object in R, we can follow the below steps −First of all, create a data.table object.Then, use rowSums function and ncol function along with apply function to find the percent of NAs in each row of the data.table object.ExampleCreate the data.table objectLet’s create a data.table object as shown below −library(data.table) x1
To remove rows in R data frame that contains a specific number, we can follow the below steps −First of all, create a data frame.Then, use single square subsetting with apply function to remove rows that contains a specific number.ExampleCreate the data frameLet’s create a data frame as shown below −x
To display legend in base R with different colors, we can follow the below steps −First of all, create a plot using plot function.Then, use legend function legend argument and col argument to display legend with different colors.ExampleCreate the plotLet’s create a plot of a vector x using plot function −x
To repeat column values of a data.table object by values in another column, we can follow the below steps −First of all, create a data.table object.Then, use rep function along with cbind function to repeat column values in the matrix by values in another column.ExampleCreate the data.table objectLet’s create a data.table object as shown below −library(data.table) x
To find the mean of a column summarized by other column names and common values in those columns in R data frame, we can follow the below steps −First of all, create a data frame.Then, melt the data frame using melt function from reshape2 package.After that, use dcast function to find the mean of a column summarized by other column names and common values in those columns.ExampleCreate the data frameLet’s create a data frame as shown below −S.No