79 lines
2.2 KiB
OCaml
79 lines
2.2 KiB
OCaml
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(* Example due to JB. Jeannin - zero-crossing detection. *)
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(* The same as [sin1x.ml] but with an integrator.
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d(t . (sin(1/t))^2))/dt = sin(1/t)(sin(1/t) - (2 . cos(1/t)) / t)
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d(sin(f(x)))/dx = cos(f(x)) f'(x) *)
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open Hsim.Types
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open Solvers.Zls
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(* let hybrid sin_1_x() =
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let der t0 = 1.0 init 0.0 in
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let d = 0.6 in
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let t = t0 -. d in
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let der o = sin(1.0 /. t) *. (sin(1.0 /. t) -. (2.0 *. cos(1.0 /. t)) /. t)
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init (-. d *. (sin(1.0 /. (-. d))) ** 2.0) in
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present up(o) -> 1.0 else 0.0, o *)
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let of_array a = Bigarray.Array1.of_array Bigarray.Float64 Bigarray.c_layout a
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type ('a, 'b) state = { s_x: 'a; zin: 'b }
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let d = 0.66
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let y0 = -. d *. let v = (sin(1.0 /. (-. d))) in v *. v
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let csize = 2
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let zsize = 1
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let fder d y yd =
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yd.{0} <- 1.0;
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let t = y.{0} -. d in
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yd.{1} <- sin(1.0 /. t) *. (sin(1.0 /. t) -. (2.0 *. cos(1.0 /. t)) /. t)
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let fzer z y zout =
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let o = y.{1} in
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zout.{0} <- if z then o else 1.0
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let fout s y =
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let z = if s.zin.{0} = 1l then 1.0 else 0.0 in
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let o = y.{1} in
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of_array [| z; o |]
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let step ({ s_x; zin } as s) zfalse =
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let z = if zin.{0} = 1l then 1.0 else -1.0 in
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let o = s_x.{1} in
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of_array [| z; o |], { s with zin = zfalse }
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let reset _ s = s
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let cget { s_x; _ } = s_x
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let cset s l_x = { s with s_x = l_x }
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let zset s zin = { s with zin }
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let horizon _ = max_float
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let jump _ = true
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let sin_1_x z d =
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let zfalse = zmake 1 in
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let yd = cmake 2 in
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let zout = cmake 1 in
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let fder _ _ y = fder d y yd; yd in
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let fzer _ _ y = fzer z y zout; zout in
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let fout s _ y = fout s y in
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let step s _ = step s zfalse in
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let state = { s_x = of_array [| 0.0; y0 |]; zin = zfalse } in
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{ state; fder; fzer; fout; step; horizon;
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cset; cget; zset; csize; zsize; reset; jump }
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let errmsg_many = "Too many arguments to model (needed: [bool, float])"
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let errmsg_few = "Too few arguments to model (needed: [bool, float])"
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let errmsg_invalid = "Invalid arguments to model (needed: [bool, float])"
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let init = function
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| [zer; d] ->
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let zer, d = try bool_of_string zer, float_of_string d
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with _ -> raise (Invalid_argument errmsg_invalid) in
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HNode (sin_1_x zer d)
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| [] | [_] -> raise (Invalid_argument errmsg_few)
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| _ -> raise (Invalid_argument errmsg_many)
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