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Articles by Nizamuddin Siddiqui
Page 21 of 196
How to create a column of factorial values in data frames stored in R list?
To create a column of factorial values 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 factorial values 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 MoreFind the count of unique group combinations in an R data frame.
To find the count of unique group combinations in an R data frame, we can use count function of dplyr package along with ungroup function.For Example, if we have a data frame called df that contains three grouping columns say G1, G2, and G3 then we can count the unique group combinations in df by using the below given command −count(df,G1,G2,G3)%%ungroup()Example 1Following snippet creates a sample data frame −Grp1
Read MoreHow to create a column of absolute values in data frames stored in R list?
To create a column of absolute values 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 absolute values 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 find the cumulative sum of columns if some columns are categorical in R data frame?
To find the cumulative sums if some columns are categorical in R data frame, we can follow the below steps −First of all, create a data frame.Then, use numcolwise function from plyr package to find the cumulative sums if some columns are categorical.ExampleCreate the data frameLet’s create a data frame as shown below −Gender
Read MoreHow to create a column of exponent in data frames stored in R list?
To create a column of exponent 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 exponent 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 create a column of log with base 10 in data frames stored in R list?
To create a column of log with base 10 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 log with base 10 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 combine matrix rows alternately in R?
If we have multiple matrices and we want to combine the rows of those matrices alternately then we would first need to find the order of the matrices with order function along with sequence and sapply function after reading the matrices with list after that the values will be combined with rbind function.Check out the Example given below to understand how it can be done.ExampleFollowing snippet creates a sample matrix −M1
Read MoreReplace all values in an R data frame if they are greater than a certain value.
To replace all values in an R data frame if they are greater than a certain value, we can use apply function with ifelse function.For Example, if we have a data frame called df and we want to replace all values in df with 5 if they are greater than 10 then we can use the command given below −df[]
Read MoreHow to deal with hist.default, 'x' must be numeric in R?
The error hist.default, 'x' must be numeric occurs when we pass a non-numerical column or vector to the hist function. If we have a non-numerical column in a data frame or a non-numerical vector and we want to create the histogram of that data can be created with the help of barplot and table function.Check out the below given Exampleto understand how it can be done.ExampleFollowing snippet creates a sample data frame −x
Read MoreCreate a data frame with numerical as well as factor columns in R.
To create a data frame with numerical as well as factor columns in R, we simply need to add factor function before factor columns and numerical columns will be created without mentioning any specific characteristics, the values of numerical columns just need to be numerical in nature.Example 1Following snippet creates a sample data frame df1 with factor and numerical column −Gender
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