Once the states are layed out on a grid, we may be interested in comparing some trends in between states. To achieve this, we create a sub projection which will be applied to all the cities inside each state:

The subprojection defines a 2D graph of housing cost vs. climate for each state in the data set. Notice that in some states like California (CA) or Washington (WA), there is a correlation between both variables, whereas in other states like Colorado (CO) or Alabama (AL), there is no such correlation.