Use else instead of finally clause in read()
Add global default parameter values

For the plot title and the output PNG file name.
Add plot_samples()

Displays a scatterplot of the locations of LHS samples.
Add plot_irregular_surface()

TODO: Need to figure out how to pass and use parameter bounds in grid.grid_lhs.
Add grid_lhs()

Uses scipy.interpolate.griddata to interpolate irregular LHS samples
and a Dakota response to a regular grid.