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To select data frame columns based on their class in R, we can follow the below steps −First of all, create a data frame or consider an inbuilt data set.Then, use select_if function of dplyr package with class function.Example 1str(CO2)OutputOn executing, the above script generates the below output(this output will vary on your system due to randomization) −Classes ‘nfnGroupedData’, ‘nfGroupedData’, ‘groupedData’ and 'data.frame':84 obs. of 5 variables: $ Plant : Ord.factor w/ 12 levels "Qn1"
To create a histogram for uniform data in R, we can simply use hist function but the bars size may vary even if the frequency is same. Therefore, for this purpose, we need to define the breaks as shown in the below example.ExampleTo create a histogram for uniform data in R, use the code given below −hist(1:6)OutputIf you execute the above given code, it generates the following output −To create a histogram for uniform data in R, use the code given below −hist(1:8) OutputIf you execute the above given code, it generates the following output −To create a histogram for ... Read More
To find the smallest number in an R data frame column excluding values zero or less, we can use min function along with subsetting of values greater than 0 through single square brackets.For example, if we have a data frame called df that contains a column say X then the smallest number excluding values zero or less can be found by using the below command −min(df[df$X>0,1])Example 1Following snippet creates a sample data frame −x
To find the dot product of two matrices in R, we can use dot function of geometry package.For Example, if we have two matrices say matrix1 and matrix2 then we can use the dot product of these two matrices by using the below given command −dot(matrix1,matrix2)Example 1Following snippet creates a sample matrix −M1
The empirical distribution can be found by using the function ecdf and if we want to create a plot of empirical distribution then plot function will be used.For example, if we have a vector called X then plot of empirical distribution can be created by using the below command −plot(ecdf(X))Example 1To create a plot of empirical distribution in R, use the code given below −x
To create sequential index value for binary column assigning 0 to FALSE values in data.table object in R, we can follow the below steps: −First of all, create a data.table object with binary column.Then, use rle function along with sequence and lengths function to create sequential index column.ExampleCreate the data.table objectLet’s create a data.table object as shown below −library(data.table) x
When we create a general linear model for logistic regression model, we need to specify the distribution family as binomial. The error “NA/NaN/Inf” occurs when we do not specify the distribution family. Hence, family="binomial" needs to be used inside glm function while creating the logistic regression model.Example 1Following snippet creates a sample data frame −iv1
To repeat a whole matrix in R, we can follow the below steps −First of all, create a matrix.Then, use rep function to repeat the matrix.ExampleCreate the matrixLet’s create a matrix as shown below −M
To separate a first text value and the remaining text in R data frame column values, we can follow the below steps −First of all, create a data frame.Then, use str_split function from stringr package to separate first text value and the remaining text.ExampleCreate the data frameLet’s create a data frame as shown below −Names
To split a number into digits in R, we can use strsplit function by reading the number with as.character and then reading the output with as.numeric.For example, if we have a number stored into an object called X then we can split the number stored in X into digits by using the command as follows −as.numeric(strsplit(as.character(X),"")[[1]])Example 1To split a number into digits in R, use the snippet given below −x1