In the previous recipe, we familiarized ourselves with heat map functions in R using built-in data. Now, we will learn how to use external data to create our heat maps.
In real life, we often have no control over the format of the data files that we download, or the data that is the output of a particular program. Because we can not always rely on luck that the data comes in the right format, we will learn in this recipe how to read in data from different file formats and get it into shape.
The following image shows a heat map that we are going to create from the
gene_expression.txt data set in this recipe:
Download the script
5644OS_02_01.r and the data sets