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Articles by Nizamuddin Siddiqui
Page 5 of 196
How to remove a column from matrix in R by using its name?
To remove a column from matrix in R by using its name, we can follow the below steps −First of all, create a matrixThen, add names to columns of the matrix.After that, subset the matrix by deselecting the desired column with negation and single square brackets for subsetting.ExampleCreate the matrixLet’s create a matrix as shown below −M
Read MoreHow to find the row total of columns having same name in data.table object in R?
To find the row total of columns having same name in data.table object in R, we can follow the below steps −First of all, create a data.table with some columns having same name.Then, use tapply along with colnames and sum function to find the row total of columns having same name.ExampleCreate the data.tableLet’s create a data.table as shown below −library(data.table) DT
Read MoreHow to extract the last n values of all elements of a list in R?
To extract the last n values of all elements of a list in R, we can follow the below steps −First of all, create a list.Then, use tail function with sapply function to extract the last n values of all elements in the list.Example 1Create the listLet’s create a list as shown below −List1
Read MoreHow to apply two sample t test using a categorical column in R data frame?
To apply two sample t test using a categorical column in R data frame, we can follow the below steps −First of all, create a data frame.Then, use t.test function with categorical column and numerical column linked with ~ sign.ExampleCreate the data frameLet’s create a data frame as shown below −Gender
Read MoreHow to create a column of product in data frames stored in R list?
To create a column of product in data frames stored in R list, we can follow the below steps −First of all, create a list of data frames.Then, use lapply function to create a column of product in data frames stored in the list.ExampleCreate the list of data framesUsing data.frame function to create data frames and list function to create the list of those data frames −df1
Read MoreHow to replace NAs with 0 in an R list that contains data.table objects?
To replace NAs with 0 in an R list that contains data.table objects, we can follow the below steps −First of all, create a list of data.table objects that contain some NAs.Then, use lapply function and is.na function to replace NAs with 0 in the list.ExampleCreate the listLet’s create a list as shown below −library(data.table) DT1
Read MoreHow to remove hash sign at last position from every value in R data frame column?
To remove hash at last position from every value in R data frame column, we can follow the below steps −First of all, create a data frame with a column having hash at last position in every value.Then, use gsub function to remove hash at last position from every value in the column.ExampleCreate the data frameLet’s create a data frame as shown below −x
Read MoreHow to find the percentage of each category in an R data frame column?
To find the percentage of each category in an R data frame column, we can follow the below steps −First of all, create a data frame.Then, use summarise function of dplyr package after grouping along with n and nrow.ExampleCreate the data frameLet’s create a data frame as shown below −Group
Read MoreHow to find the number of columns where all row values are equal in R data frame?
To find the number of columns where all row values are equal in R data frame, we can follow the below steps −First of all, create a data frame.Then, use sum function along with length and apply function to find the number of columns where all row values are equal.Example 1Create the data frameLet’s create a data frame as shown below −x
Read MoreHow to create histogram with varying binwidth using ggplot2 in R?
To create histogram with varying binwidth using ggplot2 in R, we can follow the below steps −First of all, create a data frame.Then, use geom_histogram function with breaks argument having varying differences.ExampleCreate the data frameLet’s create a data frame as shown below −x
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