Joining datasets

Having created a scripted dataset, it is a simple matter to point it to new data: copy and paste the dataset in BIRT; rename it; rename the columns as appropriate.
 
We can now use scripted datasets to access 2011 CIAWF files for GDP (rawdata_2001.txt) and Population Growth Rate (rawdata_2002.txt). We can look at this data in a scatter chart to see if there is any correlation:

GDP versus Population growth rate.
NB: Log scale used for GDP!

The answer looks to be that there is very little relationship between the two values. However, we can see that large population growth (> 2%) is not observed for either very low or very high GDPs. Whatever that might mean.

 In order to create the chart, we need more than the two scripted datasets - we also needed to join them together. Fortunately, BIRT allows us to use a "Joint Data Set". The joint dataset allows us to take 2 datasets within BIRT and define a join (inner or outer!) between them.

This then links our GDP data to the Population Growth data and allows us to create the scatter chart.