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To find the percentage of zeros in each column of a data frame in R, we can follow the below steps −First of all, create a data frame.Then, use colSums function along with nrow function to find the percentage of zeros in each column.Example 1Create the data frameLet’s create a data frame as shown below −x
To multiply corresponding values from two data frames in R, we can follow the below steps −First of all, create two data frames.Then, use mapply function to multiply corresponding values from those two data frames.ExampleCreate the first data frameLet’s create a data frame as shown below −df1
To subset a matrix in R by ignoring a value in one of the columns, we can follow the below steps −First of all, create a matrix.Then, use single square brackets to subset the matrix by ignoring a value in one of the columns.ExampleCreate the matrixLet’s create a matrix as shown below −M
To create a column of first non-zero value in each row of an R data frame, we can follow the below steps −First of all, create a data frame with some zero values.Then, use apply function and a custom function to find the first non-zero in each row of the data frame.ExampleCreate the data frameLet’s create a data frame as shown below −x
To unsplit a split data.table object in R, we can follow the below steps −First of all, create a data.table object.Then, use split function to split the data.table object.After that, use do.call function along with rbind function unsplit the data frame.ExampleCreate the data.table objectLet’s create a data.table object as shown below −library(data.table) Grp
To standardize multiple columns not all in data.table object in R, we can follow the below steps −First of all, create a data.table object.Then, subset the columns with single square brackets and use lapply, list and scale function to standardize those columns.ExampleCreate the data.table objectLet’s create a data.table object as shown below −library(data.table) x
To create ggplot2 graph with reversed Y-axis and X-axis on top, we can use scale_y_reverse and scale_x_continuous function of ggplot2 package.For Example, if we have a data frame called df that contains two columns say X and Y and we want to create the scatterplot between X and Y with reversed Y-axis and X-axis on top then we can use the below command −ggplot(df,aes(X,Y))+geom_point()+scale_y_reverse()+scale_x_continuous(position="top")ExampleFollowing snippet creates a sample data frame −x
To create correlation matrix plot without variables labels in R, we can use tl.pos argument set to n.For Example, if we have a correlation matrix say M then we can create the correlation matrix plot without variables labels by using the below command −corrplot(M,tl.pos='n')ExampleFollowing snippet creates a sample data frame −x
To create bar plot with gradient colors using ggplot2, we can use scale_fill_gradient function where we can set the lower and higher color values.For Example, if we have a data frame called df that contains two columns say Cat and Count then we can create the bar plot with gradient colors by using the below command −ggplot(df,aes(Cat,Count,fill=Cat))+geom_bar(stat="identity")+scale_fill_gradient(low="blue",high="red")ExampleFollowing snippet creates a sample data frame −x
To create a ggplot2 graph with darker axes labels, darker lines, and dark titles, we can use theme_classic function of ggplot2 package with base_size argument set to a larger value.For Example, if we have a data frame called df that contains two columns say x and y then we can create the scatterplot between x and y using ggplot2 with darker axes labels, darker lines, and dark titles by using the below command −ggplot(df,aes(x,y))+geom_point()+theme_classic(base_size=22)ExampleFollowing snippet creates a sample data frame −x