Improve control functionality

[ellessenne]

I should re-implement the control logic, e.g., see the implementation of survival::coxph.control:

survival::coxph.control
#> function (eps = 1e-09, toler.chol = .Machine$double.eps^0.75, 
#>     iter.max = 20, toler.inf = sqrt(eps), outer.max = 10, timefix = TRUE) 
#> {
#>     if (iter.max < 0) 
#>         stop("Invalid value for iterations")
#>     if (eps <= 0) 
#>         stop("Invalid convergence criteria")
#>     if (eps <= toler.chol) 
#>         warning("For numerical accuracy, tolerance should be < eps")
#>     if (toler.inf <= 0) 
#>         stop("The inf.warn setting must be >0")
#>     if (!is.logical(timefix)) 
#>         stop("timefix must be TRUE or FALSE")
#>     list(eps = eps, toler.chol = toler.chol, iter.max = as.integer(iter.max), 
#>         toler.inf = toler.inf, outer.max = as.integer(outer.max), 
#>         timefix = timefix)
#> }
#> <bytecode: 0x7fda8182a3c8>
#> <environment: namespace:survival>

^{Created on 2023-05-27 with reprex v2.0.2}