Chains two solvers sequentially. The result of the first solver becomes the starting point for the second. This enables coarse-to-fine strategies.
Examples
# Coarse-to-fine: grid search to find good region, then gradient ascent
strategy <- grid_search(n = 5) %>>% gradient_ascent()
#> Error in grid_search(n = 5): argument "lower" is missing, with no default
# Three-stage refinement
strategy <- grid_search(n = 3) %>>% gradient_ascent() %>>% newton_raphson()
#> Error in grid_search(n = 3): argument "lower" is missing, with no default