feat: a lot of stuff

src/lib/solvers/statefulSundials.ml

@@ -0,0 +1,71 @@
+(*
+open Hsim.Types
+open Hsim.Solver
+open Zls
+
+module Functional : Csolver.Csolver =
+  struct
+    type ('state, 'vec) state = { state : 'state; vec : 'vec }
+    type session = (Sundials_RealArray.t, Nvector_serial.kind) Cvode.session
+    type vec = carray
+
+    let csolve : ((session, vec) state, carray, carray) csolver =
+      let open Cvode in
+
+      let init { size; fder=_; _ } =
+        let vec = cmake size in
+        let state = init Adams default_tolerances (fun _ _ _ -> ()) 0.
+                         (Nvector_serial.wrap vec) in
+        set_stop_time state 1.0;
+        { state; vec } in
+
+      let reset { init=i; fder; stop; _ } { vec; _ } =
+        let fder t cvec dvec =
+          let dvec' = fder t cvec in blit dvec' dvec in
+        let state =
+          Cvode.init Adams default_tolerances fder 0. (Nvector_serial.wrap i) in
+        set_stop_time state stop;
+        { state; vec } in
+
+      let step ({ state; vec } as s) h =
+        let y = Nvector_serial.wrap vec in
+        let h, _ = solve_one_step state h y in
+        let f t = get_dky state y t 0; Nvector_serial.unwrap y in
+        (h, f), s in
+
+      DNode { init; reset; step }
+  end
+
+module InPlace : Csolver.Csolver =
+  struct
+    type ('state, 'vec) state = { mutable state: 'state; mutable vec : 'vec }
+
+    type session = (Sundials_RealArray.t, Nvector_serial.kind) Cvode.session
+    type vec = carray
+
+    let csolve : ((session, vec) state, carray, carray) csolver =
+      let open Cvode in
+
+      let init { size; fder=_; _ } =
+        let vec = cmake size in
+        let state = init Adams default_tolerances (fun _ _ _ -> ()) 0.
+                         (Nvector_serial.wrap vec) in
+        set_stop_time state 1.0;
+        { state; vec } in
+
+      let reset { init=i; fder; _ } s =
+        let fder t cvec dvec =
+          let dvec' = fder t cvec in blit dvec' dvec in
+        let state =
+          Cvode.init Adams default_tolerances fder 0. (Nvector_serial.wrap i) in
+        set_stop_time state 1.0; s.state <- state; s.vec <- i; s in
+
+      let step s h =
+        let y = Nvector_serial.wrap s.vec in
+        let h, _ = solve_one_step s.state h y in
+        let f t = get_dky s.state y t 0; Nvector_serial.unwrap y in
+        (h, f), s in 
+
+      DNode { init; reset; step }
+  end
+*)