feat: solvers and ball example

src/bin/main.ml

@@ -1,4 +1,49 @@
-open Hsim.Types
 
-let _x : 'a value = { start = 0.; length = 0.; u = (fun _ -> 0) }
-let () = print_endline "Hello, World!"
+open Hsim
+open Examples
+open Types
+
+let sample = ref 10
+let stop   = ref 30.0
+let debug  = ref false
+
+let doc_sample = "n \tSample count [10]"
+let doc_stop   = "n \tStop time [10.0]"
+let doc_debug  = "\tPrint debug information"
+
+let opts = [
+  "-sample", Arg.Set_int sample, doc_sample;
+  "-stop", Arg.Set_float stop, doc_stop;
+  "-debug", Arg.Set debug, doc_debug
+]
+
+let errmsg = "Usage: " ^ Sys.executable_name ^ " [OPTIONS]\nOptions are:"
+
+let () =
+  try Arg.parse (Arg.align opts) (fun _ -> ()) errmsg
+  with _ -> exit 2
+
+let print_samples n { start; length; u } =
+  if !debug then begin
+    if length <= 0.0 then
+      Format.printf "\nD : %.20e\n\n" start
+    else Format.printf "\nC : %.20e to %.20e\n\n" start (start +. length);
+  end;
+  Format.printf "%.20e\t% .20e\n" start (u 0.0).{0};
+  if length <= 0.0 then ()
+  else let step = length /. (float_of_int n) in
+  let rec loop i =
+    if i > n then ()
+    else let t = float_of_int i *. step in
+    (Format.printf "%.20e\t" (start +. t); Format.printf "% .20e\n" (u t).{0};
+     loop (i+1)) in
+  loop 1
+
+let () =
+  let csolver = StatefulRK45.Functional.csolve in
+  let zsolver = StatefulZ.Functional.zsolve in
+  let solver = Solver.solver_c csolver zsolver in
+  let model = Ball.bouncing_ball () in
+  let open Sim.LazySim(State.FunctionalSimState) in
+  run_until model (Solver.solver_from_c solver) !stop (print_samples !sample)
+