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Articles by Nizamuddin Siddiqui
Page 141 of 196
How to remove dollar sign in R data frame?
To remove dollar sign in R data frame, we can follow the below steps −First of all, create a data frame.Then, use gsub function along with lapply function to remove dollar sign.ExampleCreate the data frameLet’s create a data frame as shown below −Product
Read MoreHow to find the number of changes when tossing a coin in R?
To find the number of changes when tossing a coin in R, we can follow the below steps −First of all, create a vector using rbinom function.Then, use rle function to find the table of changes.After that, use length in the output of rle.Example 1Create the vectorLet’s create a vector as shown below −x1
Read MoreHow to find the column means if some columns are categorical in R data frame?
To find the column means 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 column means ifsome columns are categorical.Example 1Create the data frameLet’s create a data frame as shown below −Grp
Read MoreConvert list with varying number of elements into a data frame.
To convert list with varying number of elements into a data frame in R, we can use stri_list2matrix function of stringi package along with as.data.frame function.For Example, if we have a list called LIST that contains varying number of elements then we can convert it into a data frame by using the below mentioned command −as.data.frame(t(stri_list2matrix(LIST)))Example 1Following snippet creates a sample list −List1
Read MoreHow to multiply vector values in sequence with matrix columns in R?
To multiply vector values in sequence with matrix columns in R, we can follow the below steps −First of all, create a matrix.Then, create a vector.After that, use t function for transpose and multiplication sign * to multiply vector values in sequence with matrix columns.ExampleCreate the data frameLet’s create a data frame as shown below −M
Read MoreHow to find the frequency of each value in an R data frame?
To find the frequency of each value in an R data frame, we can use table function along with unlist function.For Example, if we have a data frame called df and we want to find the frequency of each value in df then we can use the below command −table(unlist(df))Example 1Following snippet creates a sample data frame −x1
Read MoreHow to convert alphabets to numbers in data.table object in R?
To convert alphabets to numbers in data.table object in R, we can follow the below steps −First of all, create a data.table object.Then, use mutate_each function of dplyr package along with chartr function to convert alphabets to numbers.ExampleCreate the data.table objectLet’s create a data.table object as shown below −library(data.table) v1
Read MoreHow to find the percentage of values that lie within a range in R data frame column?
To find the percentage of values that lie within a range in R data frame column, we can follow the below steps −First of all, create a data frame.Then, use sum function along with extreme values for range and length function to find the percentage of values that lie within that range.ExampleCreate the data frameLet’s create a data frame as shown below −Var
Read MoreHow to find the total by year column in an R data frame?
To find the total by year column in an R data frame, we can use aggregate function with sum function.For Example, if we have a data frame called df that contains a year colmn say Year and a numerical column say Demand then we can find the total Demand by Year with the help of command given below −aggregate(df["Demand"],by=df["Year"],sum)Example 1Following snippet creates a sample data frame −Year
Read MoreHow to standardize selected columns in data.table object in R?
To standardize selected columns in data.table object in R, we can follow the below steps −First of all, create a data.table object.Then, use scale function and cbind function with subsetting to standardize selected columns.ExampleCreate the data.table objectLet’s create a data.table object as shown below −library(data.table) var1
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