Return the data frame containing the gradients for all parameters.
gradients()A list of lists. See Examples.
# \dontrun{
test <- cmdstanr_example("logistic", method = "diagnose")
# retrieve the gradients
test$gradients()
#> param_idx value model finite_diff error
#> 1 0 -1.816810 37.64170 37.64170 -8.16570e-10
#> 2 1 0.376746 -18.33100 -18.33100 -3.03892e-08
#> 3 2 0.477942 -15.36460 -15.36460 -2.99484e-08
#> 4 3 1.852310 -7.94121 -7.94121 -3.99522e-08
# }