9 Customise the first wave

This section consists of just one task: it is time to put all you have learnt so far to good use!

Task

Now that we have learnt how to customise the various steps of the process, try to improve the performance of the first wave of emulation and history matching. First, have a look at the emulator diagnostics and see if you can improve the performance of the emulators. Then generate new points using your improved emulators.

Solution

First of all let us take a look at the diagnostics of all the emulators trained in wave 1:

vd <- validation_diagnostics(ems_wave1, validation = validation, 
                             targets = targets, plt=TRUE)

Most emulators would benefit from having slightly more conservative emulators, which we can obtain by increasing \(\sigma\). After some trial and error, we chose the following values of sigma for our emulators:

inflations <- c(1.5,1.5,1,1,1,1,1.5,1.5,2,2,1.5,2)
for (i in 1:length(ems_wave1)) {
  ems_wave1[[i]] <- ems_wave1[[i]]$mult_sigma(inflations[[i]])
}

vd <- validation_diagnostics(ems_wave1, validation = validation, 
                             targets = targets, plt=TRUE)

The diagnostics look good now, so we can use the current emulators to generate new points:

new_points <- generate_new_design(ems_wave1, 180, targets, verbose = TRUE)

## Proposing from LHS...
## LHS has high yield; no other methods required.
## Selecting final points using maximin criterion...