Although Hadoop jobs can generate interesting analytics, making sense of those results and getting a detailed understanding about the data often require us to see the overall trends in the data. We often do that by plotting the data.
The human eye is remarkably good at detecting patterns, and plotting the data often yields us a deeper understanding of the data. Therefore, we often plot the results of Hadoop jobs using some plotting program.
This recipe explains how to use GNU Plot, which is a free and powerful plotting program, to plot Hadoop results.
This recipe assumes that you have followed the previous recipe, Calculating frequency distributions and sorting using MapReduce. If you have not done so, please follow the recipe.
We will use the
HADOOP_HOME
variable to refer to the Hadoop installation folder.Install the GNU Plot plotting program by following the instructions in http://www.gnuplot.info/.