Annotation of OpenXM_contrib/PHC/Ada/Root_Counts/Dynlift/enumerate_faces_of_polytope.adb, Revision 1.1
1.1 ! maekawa 1: with Integer_Face_Enumerators; use Integer_Face_Enumerators;
! 2:
! 3: package body Enumerate_Faces_of_Polytope is
! 4:
! 5: -- UTILITIES :
! 6:
! 7: function Is_In ( i : natural; v : Vector ) return boolean is
! 8: begin
! 9: for j in v'range loop
! 10: if v(j) = i
! 11: then return true;
! 12: end if;
! 13: end loop;
! 14: return false;
! 15: end Is_In;
! 16:
! 17: -- TARGET ROUTINES :
! 18:
! 19: procedure Enumerate_Faces_in_List
! 20: ( l : in List; point : in Link_to_Vector; k : in natural ) is
! 21:
! 22: verpts : constant VecVec := Shallow_Create(l);
! 23: face : VecVec(0..k);
! 24:
! 25: procedure Enumerate_Vertices ( l,start : in natural ) is
! 26:
! 27: -- DESCRIPTION :
! 28: -- Already l vectors have been choosen out of verpts and
! 29: -- are in face(0..l). In indices(0..l) the position of the
! 30: -- ith face in the vector of vertices is given by indices(i).
! 31: -- The parameter start indices from which vertex on, the
! 32: -- enumeration has to start.
! 33: -- In this way, the faces are enumerated in lexicographic order.
! 34:
! 35: begin
! 36: if l >= k
! 37: then Process(face);
! 38: elsif (verpts'last-start+1) >= k-l
! 39: then
! 40: for j in start..verpts'last loop
! 41: face(l+1) := verpts(j);
! 42: Enumerate_Vertices(l+1,j+1);
! 43: end loop;
! 44: end if;
! 45: end Enumerate_Vertices;
! 46:
! 47: begin
! 48: face(0) := point;
! 49: Enumerate_Vertices(0,verpts'first);
! 50: end Enumerate_Faces_in_List;
! 51:
! 52: procedure Enumerate_Lower_Faces_in_List
! 53: ( l : in List; point : in Link_to_Vector; k : in natural ) is
! 54:
! 55: verpts : VecVec(1..Length_Of(l)+1);
! 56: face : VecVec(0..k);
! 57:
! 58: begin
! 59: verpts(1) := point;
! 60: verpts(2..verpts'last) := Shallow_Create(l);
! 61: face(0) := point;
! 62: if k = 1
! 63: then
! 64: declare
! 65: procedure Low_Edge ( i,j : in integer; cont : out boolean ) is
! 66: begin
! 67: if i = 1
! 68: then face(1) := verpts(j);
! 69: Process(face); cont := true;
! 70: else cont := false;
! 71: end if;
! 72: end Low_Edge;
! 73: procedure Enum_Low_Edges is new Enumerate_Lower_Edges(Low_Edge);
! 74: begin
! 75: Enum_Low_Edges(verpts);
! 76: end;
! 77: else
! 78: declare
! 79: procedure Low_Face ( f : in Vector; cont : out boolean ) is
! 80: begin
! 81: if f(f'first) = 1
! 82: then for i in 1..f'last loop
! 83: face(i) := verpts(f(i));
! 84: end loop;
! 85: Process(face); cont := true;
! 86: else cont := false;
! 87: end if;
! 88: end Low_Face;
! 89: procedure Enum_Low_Faces is new Enumerate_Lower_Faces(Low_Face);
! 90: begin
! 91: Enum_Low_Faces(k,verpts);
! 92: end;
! 93: end if;
! 94: end Enumerate_Lower_Faces_in_List;
! 95:
! 96: procedure Enumerate_Faces_in_Simplex
! 97: ( s : in Simplex; point : in Link_to_Vector; k : in natural ) is
! 98:
! 99: verpts : constant VecVec := Vertices(s);
! 100: face : VecVec(0..k);
! 101: indices : Vector(0..k);
! 102:
! 103: procedure Enumerate_Vertices ( l,start : in natural ) is
! 104:
! 105: -- DESCRIPTION :
! 106: -- Already l vectors have been choosen out of verpts and
! 107: -- are in face(0..l). In indices(0..l) the position of the
! 108: -- ith face in the vector of vertices is given by indices(i).
! 109: -- The parameter start indices from which vertex on, the
! 110: -- enumeration has to start.
! 111: -- In this way, the faces are enumerated in lexicographic order.
! 112:
! 113: begin
! 114: if l >= k
! 115: then Process(face);
! 116: elsif (verpts'last-start+1) >= k-l
! 117: then
! 118: for j in start..verpts'last loop
! 119: if not Is_In(j,indices(0..l))
! 120: then indices(l+1) := j;
! 121: face(l+1) := verpts(j);
! 122: Enumerate_Vertices(l+1,j+1);
! 123: end if;
! 124: end loop;
! 125: end if;
! 126: end Enumerate_Vertices;
! 127:
! 128: begin
! 129: -- SEARCH FOR THE INDEX OF THE POINT :
! 130: indices(0) := verpts'first - 1;
! 131: for i in verpts'range loop
! 132: if verpts(i).all = point.all
! 133: then indices(0) := i;
! 134: end if;
! 135: exit when indices(0) >= verpts'first;
! 136: end loop;
! 137: -- ENUMERATE ALL OTHER k CHOICES OF POINTS :
! 138: if indices(0) >= verpts'first
! 139: then
! 140: face(0) := point;
! 141: Enumerate_Vertices(0,verpts'first);
! 142: end if;
! 143: end Enumerate_Faces_in_Simplex;
! 144:
! 145: procedure Enumerate_Lower_Faces_in_Simplex
! 146: ( s : in Simplex; point : in Link_to_Vector; k : in natural ) is
! 147:
! 148: verpts : constant VecVec := Vertices(s);
! 149: face : VecVec(0..k);
! 150: indices : Vector(0..k);
! 151:
! 152: begin
! 153: null;
! 154: end Enumerate_Lower_Faces_in_Simplex;
! 155:
! 156: procedure Enumerate_Faces_in_Triangulation
! 157: ( t : in Triangulation;
! 158: point : in Link_to_Vector; k : in natural ) is
! 159:
! 160: verpts : constant VecVec := Vertices(t,point.all);
! 161: face : VecVec(0..k);
! 162: indices : Vector(0..k);
! 163:
! 164: procedure Enumerate_Vertices ( l,start : in natural ) is
! 165:
! 166: -- DESCRIPTION :
! 167: -- Already l vectors have been choosen out of verpts and
! 168: -- are in face(0..l). In indices(0..l) the position of the
! 169: -- ith face in the vector of vertices is given by indices(i).
! 170: -- The parameter start indices from which vertex on, the
! 171: -- enumeration has to start.
! 172: -- In this way, the faces are enumerated in lexicographic order.
! 173:
! 174: begin
! 175: if l >= k
! 176: then Process(face);
! 177: elsif (verpts'last-start+1) >= k-l
! 178: then
! 179: for j in start..verpts'last loop
! 180: if not Is_In(j,indices(0..l))
! 181: then indices(l+1) := j;
! 182: face(l+1) := verpts(j);
! 183: Enumerate_Vertices(l+1,j+1);
! 184: end if;
! 185: end loop;
! 186: end if;
! 187: end Enumerate_Vertices;
! 188:
! 189: begin
! 190: -- SEARCH FOR THE INDEX OF THE POINT :
! 191: indices(0) := verpts'first - 1;
! 192: for i in verpts'range loop
! 193: if verpts(i).all = point.all
! 194: then indices(0) := i;
! 195: end if;
! 196: exit when indices(0) >= verpts'first;
! 197: end loop;
! 198: -- ENUMERATE ALL OTHER k CHOICES OF POINTS :
! 199: if indices(0) >= verpts'first
! 200: then
! 201: face(0) := point;
! 202: Enumerate_Vertices(0,verpts'first);
! 203: end if;
! 204: end Enumerate_Faces_in_Triangulation;
! 205:
! 206: procedure Enumerate_Lower_Faces_in_Triangulation
! 207: ( t : in Triangulation;
! 208: point : in Link_to_Vector; k : in natural ) is
! 209:
! 210: verpts : constant VecVec := Vertices(t,point.all);
! 211: face : VecVec(0..k);
! 212: indices : Vector(0..k);
! 213:
! 214: begin
! 215: null;
! 216: end Enumerate_Lower_Faces_in_Triangulation;
! 217:
! 218: end Enumerate_Faces_of_Polytope;
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