Sometimes it is necessary to create an empty data frame in R to fill with output. An example would be output from a for loop that loops over SNPs and calculates an association p-value to fill into the empty data frame. The matrix functionality in R makes this easy to do. The code below will create a 100 by 2 matrix and convert it into a dataframe with 100 rows and 2 column variables. The nrow and ncol options are what designate the size of the resulting data frame. The data frame is filled with NA values so that missing values are handled appropriately. Below is some example code:
Welcome to the Genome Toolbox! I am glad you navigated to the blog and hope you find the contents useful and insightful for your genomic needs. If you find any of the entries particularly helpful, be sure to click the +1 button on the bottom of the post and share with your colleagues. Your input is encouraged, so if you have comments or are aware of more efficient tools not included in a post, I would love to hear from you. Enjoy your time browsing through the Toolbox.