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Articles by Nizamuddin Siddiqui
Page 73 of 196
How to delete a list element that only contains NA in R?
To delete a list element that only contains NA, we can use Filter function with Negate function. For example, if we have a list called LIST that contains one or more elements having all NA’s then we can delete those elements using the command −Filter(Negate(anyNA),LIST)Example1Consider the below list − Live DemoList1
Read MoreHow to find the object size in R?
To find the object size in R, we can use object.size function. For example, if we have a data frame called df then the size of df can be found by using the command object.size(df). Similarly, if we have a vector say x then it’s size can be found using object.size(x) and for a matrix M it can be object.size(M).Example1Consider the below data frame − Live Demox
Read MoreHow to detect multicollinearity in categorical variables using R?
The multicollinearity is the term is related to numerical variables. It means that independent variables are linearly correlated to each other and they are numerical in nature. The categorical variables are either ordinal or nominal in nature hence we cannot say that they can be linearly correlated.ExampleConsider the below data frame − Live Demox
Read MoreHow to find the column mean by excluding NA’s and if all values are NA then output NA in R data frame?
To find the column mean by excluding NA’s can be easily done by using na,rm but if we want to have NA if all the values are NA then it won’t be that straight forward. Therefore, in such situation, we can use ifelse function and return the output as NA if all the values are NA as shown in the below examples.Example1Consider the below data frame − Live Demox1
Read MoreHow to find the sum of non-missing values in an R data frame column?
To find the sum of non-missing values in an R data frame column, we can simply use sum function and set the na.rm to TRUE. For example, if we have a data frame called df that contains a column say x which has some missing values then the sum of the non-missing values can be found by using the command sum(df$x,na.rm=TRUE).Example1Consider the below data frame − Live Demox1
Read MoreHow to subset a data.table object using a range of values in R?
To subset a data.table object using a range of values, we can use single square brackets and choose the range using %between%. For example, if we have a data.table object DT that contains a column x and the values in x ranges from 1 to 10 then we can subset DT for values between 3 to 8 by using the command DT[DT$x %between% c(3,8)].Example1Loading data.table package and creating a data.table object −library(data.table) x1
Read MoreHow to convert a list to JSON in R?
To convert a list to JSON, we can use toJSON function of jsonlite package. For example, if we have a list called LIST then it can be converted to a JSON by using the command toJSON(LIST,pretty=TRUE,auto_unbox=TRUE). We need to make sure that the package jsonlite is loaded in R environment otherwise the command won’t work.Example Live DemoList
Read MoreHow to randomly sample rows from an R data frame using sample_n?
To randomly sample rows from an R data frame using sample_n, we can directly pass the sample size inside sample_n function of dplyr package. For example, if we have data frame called df then to create a random sample of 5 rows in df can be done by using the command −df%>%sample_n(5)Example1Consider the below data frame − Live Demox1
Read MoreHow to add a variable description in R?
To add a variable description in R, we can use comment function and if we want to have a look at the description then structure call of the data frame will be used. For example, if we have a data frame say df that contains a column x then we can describe x by using the command comment(df$x)
Read MoreHow to format all decimal places in an R vector and data frame?
To format all decimal places in an R vector and data frame, we can use formattable function of formattable package where we can specify the number of digits after decimal places. For example, if we have a numerical vector say x then the values in x can be formatted to have only 2 decimal places by using the command formattable(x,format="f",digits=2).Example1Loading formattable package −library(formattable) Live Demox1
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