#open "graphics";;
 
 
let identite n = let a = (make_matrix n n) 0 in for i=0 to n-1 do a.(i).(i)<-1 done ; a ;;
 
let sigma a b f = let s=ref 0 in for i=a to b do s:= !s+(f i) done ; !s ;;
 
let nb_li = vect_length ;;
 
let nb_col m = vect_length (m.(0));;

let s_mat a b =
if (nb_col a)<>(nb_col b) then failwith "somme matricielle non définie car nombre de colones différent"
else if (nb_li a)<>(nb_li b) then failwith "somme matricielle non définie car nombre de lignes différent"
else let p=nb_col a in let n=nb_li a in let m=make_matrix n p 0
in for i=0 to n-1 do for j=0 to p-1 do m.(i).(j)<-(a.(i).(j)+b.(i).(j)) mod 2 done done ; m ;;
 
let s_mat_li a b i = let m = make_matrix (nb_li a) (nb_col a) 0 in for j=0 to (nb_col a)-1
do m.(i).(j)<-(a.(i).(j)+b.(0).(j)) mod 2 done ; m ;;
 
let s_ele_mat m = let c=ref 0 in for i=0 to nb_li m -1 do for j=0 to nb_col m -1 do c:=!c+m.(i).(j) done done ; !c ;;
 
let p_mat a b = if (nb_col a)<>(nb_li b) then failwith "produit matriciel non défini"
else let n=nb_li a in let p=nb_col a in let q=nb_col b in
let M = make_matrix n q 0 in for i=0 to n-1 do for j=0 to q-1 do
M.(i).(j) <- ((sigma 0 (p-1) (fun k -> a.(i).(k)*b.(k).(j))) mod 2 ) done done ; M ;;
 
let gen_h = [|[|1;0;0;0;1;1;0|];
[|0;1;0;0;1;0;1|];
[|0;0;1;0;0;1;1|];
[|0;0;0;1;1;1;1|]|] ;;
 
let cod_h m= p_mat m gen_h ;;
 
let mat_ctrl_h = [|[|1;1;0|];
[|1;0;1|];
[|0;1;1|];
[|1;1;1|];
[|1;0;0|];
[|0;1;0|];
[|0;0;1|];|];;
 
let ctrl_h m = p_mat m mat_ctrl_h ;;
 
let decod m (*supprime les bits de parité*) = let p = make_matrix (nb_li m) 4 0 in for i=0 to (nb_li m)-1 do for j=0 to 3 do p.(i).(j) <- m.(i).(j) done done; p;;
 
let correction m (*décodage par syndrome à améliorer*) = let p=ref (decod m) in for i=0 to (nb_li m)-1 do if ctrl_h m == [|[|0; 0; 0|]|] || ctrl_h m == [|[|1; 0; 0|]|]
|| ctrl_h m == [|[|0; 1; 0|]|] || ctrl_h m == [|[|0; 0; 1|]|] then ()
else if ctrl_h m = [|[|1; 1; 0|]|] then p:= (s_mat_li (decod m) [|[|1; 0; 0; 0|]|] i)
else if ctrl_h m = [|[|1; 0; 1|]|] then p:= (s_mat_li (decod m) [|[|0; 1; 0; 0|]|] i)
else if ctrl_h m = [|[|0; 1; 1|]|] then p:= (s_mat_li (decod m) [|[|0; 0; 1; 0|]|] i)
else if ctrl_h m = [|[|1; 1; 1|]|] then p:= (s_mat_li (decod m) [|[|0; 0; 0; 1|]|] i) done; !p ;;
 
let err m x y (*génère sur un matrice des erreurs à un taux de x/y*) = let a = make_matrix (nb_li m) (nb_col m) 0 
in for i=0 to (nb_li m)-1 do for j=0 to (nb_col m)-1
do let b=random__int y in if b<x then a.(i).(j)<-(m.(i).(j) + 1) mod 2 else a.(i).(j)<-m.(i).(j) done done ; a;;
 
let err_bin m x y = let a = make_matrix (nb_li m) (nb_col m) [|0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0;0|]
in for i=0 to (nb_li m)-1 do for j=0 to (nb_col m)-1 do a.(i).(j)<-[|0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0;0|] done done ;
for i=0 to (nb_li m)-1 do for j=0 to (nb_col m)-1 do for k=0 to 23 do
let b=random__int y in if b<x then a.(i).(j).(k)<-(m.(i).(j).(k) + 1) mod 2 else a.(i).(j).(k)<-m.(i).(j).(k) done done done ; a;;
 
let rec puiss2 k = if k=0 then 1 else
if k mod 2=0 then let y = puiss2 (k/2) in y*y
else 2*puiss2 (k-1) ;;
 
let int_to_bin n = let res=make_vect 24 0 and m= ref n and i=ref 0 in
while !m>0 do res.(!i)<-(!m mod 2) ; m:=!m/2 ; incr i done ; res ;;
 
let bin_to_int m = let a=ref 0 in for i=0 to 23 do a:=!a+m.(i)*(puiss2 i) done ; !a ;;
 
let conv_color_bin m = let p = make_matrix (nb_li m) (nb_col m) [||] in
for i=0 to (nb_li m)-1 do for j=0 to (nb_col m)-1 
do p.(i).(j)<- int_to_bin m.(i).(j) done done ; p ;;
 
let conv_bin_color m = let p = make_matrix (nb_li m) (nb_col m) (white) in
for i=0 to (nb_li m)-1 do for j=0 to (nb_col m)-1 
do p.(i).(j)<- (bin_to_int m.(i).(j)) done done ; p ;;
 
let convert_one_bit_rbg m (*obsolète*) = let p = make_matrix (vect_length m) (nb_col m) white in for i=0 to (nb_li m)-1 do for j=0 to (nb_col m)-1 do 
if m.(i).(j)=1 then p.(i).(j)<-black done done ; p ;;
 
let n_lignes m = let n=nb_li m and m=nb_col m in match n*m mod 4 with
|0-> n*m/4
|_-> n*m/4 + 1 ;;
 
let transforme_matrice m = let p=nb_col m and n=nb_li m and k=ref 0 and l=ref 0 in 
let resultat = ref (make_matrix (n_lignes m) 4 0) in
for i=0 to (n-1) do 
for j=0 to (p-1) do 
(!resultat).(!k).(!l) <- m.(i).(j) ; if !l=3 then (l:=0 ; incr k) else incr l done done; !resultat ;;
 
let drapeau_français = let a=make_matrix 160 300 blue in for i=100 to 199 do for j=0 to 159 do a.(j).(i)<-white done done ;
for i=200 to 299 do for j=0 to 159 do a.(j).(i)<-red done done ; a ;;
 
open_graph "80x40+10-10";;
 
draw_image (make_image drapeau_français) 10 20 ;;

draw_image (make_image (conv_bin_color (err_bin (conv_color_bin drapeau_français) 1 20))) 10 20 ;;