master > master: code py - hirschberg

This commit is contained in:
RD 2022-06-09 01:51:08 +02:00
parent 53b2066e0d
commit 14a882e9d3
3 changed files with 428 additions and 10 deletions

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@ -16,6 +16,7 @@ from src.local.maths import *;
from src.graphs.graph import *;
from src.graphs.tarjan import *;
from src.travel.naive import *;
from src.string_alignment.hirschberg import *;
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# GLOBAL CONSTANTS/VARIABLES
@ -28,16 +29,22 @@ from src.travel.naive import *;
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
def enter():
## Beispiel aus Seminarblatt 8
tsp_naive_algorithm(
dist = np.asarray([
[0, 7, 2, 5],
[7, 0, 5, 6],
[2, 5, 0, 5],
[2, 7, 4, 0],
], dtype=float),
optimise=max,
verbose=True,
# ## Beispiel für Seminarwoche 9 (Blatt 8):
# tsp_naive_algorithm(
# dist = np.asarray([
# [0, 7, 4, 3],
# [7, 0, 5, 6],
# [2, 5, 0, 5],
# [2, 7, 4, 0],
# ], dtype=float),
# optimise=min,
# verbose=True,
# );
## Beispiel für Seminarwoche 10 (Blatt 9):
hirschberg_algorithm_full(
X = 'ACGAAG',
Y = 'AGAT',
verbose = True,
);
return;

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@ -0,0 +1,411 @@
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# IMPORTS
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
from __future__ import annotations;
from src.local.typing import *;
from src.local.maths import *;
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# EXPORTS
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
__all__ = [
'hirschberg_algorithm',
'hirschberg_algorithm_full',
];
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# CONSTANTS / SETUP
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
class Directions(Enum):
UNSET = -1;
DIAGONAL = 1;
HORIZONTAL = 0;
VERTICAL = 2;
def gap_penalty(x: str):
return 1;
def missmatch_penalty(x: str, y: str):
return 0 if x == y else 1;
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# METHOD hirschberg_algorithm
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
def hirschberg_algorithm(
X: str,
Y: str,
verbose: bool = False,
) -> Tuple[str, str]:
Costs, Moves = hirschberg_match_matrix(X = '-' + X, Y = '-' + Y);
path = reconstruct_optimal_path(Moves=Moves);
word_x, word_y = reconstruct_words(X = '-' + X, Y = '-' + Y, Moves=Moves, path=path);
if verbose:
L = len(word_x);
costs_repr, moves_repr = display_cost_matrix(Costs=Costs, path=path, X = '-' + X, Y = '-' + Y);
print('');
print('\x1b[1mAlignment:\x1b[0m');
print(f' {word_y}');
print(f' {L*"-"}');
print(f' {word_x}');
print('');
print(costs_repr);
print('');
print(moves_repr);
return word_x, word_y;
def hirschberg_algorithm_full(
X: str,
Y: str,
depth: int = 0,
verbose: bool = False,
) -> Tuple[str, str]:
n = len(Y);
if n > 1:
n = int(np.ceil(n/2));
# bilde linke Hälfte vom horizontalen Wort:
Y1 = Y[:n];
X1 = X;
# bilde rechte Hälfte vom horizontalen Wort (und kehre h. + v. um):
Y2 = Y[n:][::-1];
X2 = X[::-1];
# Löse Teilprobleme:
Costs1, Moves1 = hirschberg_match_matrix(X = '-' + X1, Y = '-' + Y1);
Costs2, Moves2 = hirschberg_match_matrix(X = '-' + X2, Y = '-' + Y2);
path1, path2 = reconstruct_optimal_path_halves(
Costs1=Costs1,
Costs2=Costs2,
Moves1=Moves1,
Moves2=Moves2,
);
word_x_1, word_y_1 = reconstruct_words(X = '-' + X1, Y = '-' + Y1, Moves=Moves1, path=path1);
word_x_2, word_y_2 = reconstruct_words(X = '-' + X2, Y = '-' + Y2, Moves=Moves2, path=path2);
if verbose:
L = len(word_x_1) + len(word_x_2);
costs_repr, moves_repr = display_cost_matrix_halves(
Costs1 = Costs1,
Costs2 = Costs2,
path1 = path1,
path2 = path2,
X1 = '-' + X1,
X2 = '-' + X2,
Y1 = '-' + Y1,
Y2 = '-' + Y2,
);
print('');
print(f'\x1b[1mRekursionstiefe: {depth}\x1b[0m')
print('');
print('\x1b[1mAlignment:\x1b[0m');
print(f' {word_y_1} {word_y_2[::-1]}');
print(f' {(L+1)*"-"}');
print(f' {word_x_1} {word_x_2[::-1]}');
print('');
print(moves_repr);
coord = path1[-1];
m = coord[0];
word_x_1, word_y_1 = hirschberg_algorithm_full(X=X[:m], Y=Y[:n], depth=depth+1, verbose=True);
word_x_2, word_y_2 = hirschberg_algorithm_full(X=X[m:], Y=Y[n:], depth=depth+1, verbose=True);
word_x = word_x_1 + word_x_2;
word_y = word_y_1 + word_y_2;
else:
word_x, word_y = hirschberg_algorithm(X=X, Y=Y, verbose=False);
if depth == 0:
L = len(word_x);
print('');
print('\x1b[1mAlignment:\x1b[0m');
print(f' {word_y}');
print(f' {L*"-"}');
print(f' {word_x}');
print('');
return word_x, word_y;
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# METHODS cost matrix + optimal paths
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
def hirschberg_match_matrix(
X: str,
Y: str,
) -> Tuple[NDArray[(Any, Any), int], NDArray[(Any, Any), Directions]]:
'''
Berechnet Hirschberg-Costs-Matrix (ohne Rekursion).
Annahmen:
- X[0] = gap
- Y[0] = gap
'''
m = len(X); # display vertically
n = len(Y); # display horizontally
Costs = np.full(shape=(m, n), dtype=int, fill_value=0);
Moves = np.full(shape=(m, n), dtype=Directions, fill_value=Directions.UNSET);
# zuerst 0. Spalte und 0. Zeile ausfüllen:
for i, x in list(enumerate(X))[1:]:
update_cost_matrix(Costs, Moves, x, '', i, 0);
for j, y in list(enumerate(Y))[1:]:
update_cost_matrix(Costs, Moves, '', y, 0, j);
# jetzt alle »inneren« Werte bestimmen:
for i, x in list(enumerate(X))[1:]:
for j, y in list(enumerate(Y))[1:]:
update_cost_matrix(Costs, Moves, x, y, i, j);
return Costs, Moves;
def update_cost_matrix(
Costs: NDArray[(Any, Any), int],
Moves: NDArray[(Any, Any), Directions],
x: str,
y: str,
i: int,
j: int,
):
'''
Schrittweise Funktion zur Aktualisierung vom Eintrag `(i,j)` in der Kostenmatrix.
Annahme:
- alle »Vorgänger« von `(i,j)` in der Matrix sind bereits optimiert.
@inputs
- `Costs` - bisher berechnete Kostenmatrix
- `Moves` - bisher berechnete optimale Schritte
- `i`, `x` - Position und Wert in String `X` (»vertical« dargestellt)
- `j`, `y` - Position und Wert in String `Y` (»horizontal« dargestellt)
'''
# nichts zu tun, wenn (i, j) == (0, 0):
if i == 0 and j == 0:
Costs[0, 0] = 0;
return;
################################
# NOTE: Berechnung von möglichen Moves wie folgt.
#
# Fall 1: (i-1,j-1) ---> (i,j)
# ==> Stringvergleich ändert sich wie folgt:
# s1 s1 x
# ---- ---> ------
# s2 s2 y
#
# Fall 2: (i,j-1) ---> (i,j)
# ==> Stringvergleich ändert sich wie folgt:
# s1 s1 GAP
# ---- ---> -------
# s2 s2 y
#
# Fall 3: (i-1,j) ---> (i,j)
# ==> Stringvergleich ändert sich wie folgt:
# s1 s1 x
# ---- ---> -------
# s2 s2 GAP
#
# Diese Fälle berücksichtigen wir:
################################
edges = [];
if i > 0 and j > 0:
edges.append((
Directions.DIAGONAL,
Costs[i-1, j-1] + missmatch_penalty(x, y),
));
if j > 0:
edges.append((
Directions.HORIZONTAL,
Costs[i, j-1] + gap_penalty(y),
));
if i > 0:
edges.append((
Directions.VERTICAL,
Costs[i-1, j] + gap_penalty(x),
));
if len(edges) > 0:
# Sortiere nach Priorität (festgelegt in Enum):
edges = sorted(edges, key=lambda x: x[0].value);
# Wähle erste Möglichkeit mit minimalen Kosten:
index = np.argmin([ cost for _, cost in edges]);
Moves[i, j], Costs[i, j] = edges[index];
return;
def reconstruct_words(
X: str,
Y: str,
Moves: NDArray[(Any, Any), Directions],
path: List[Tuple[int, int]],
) -> Tuple[str, str]:
word_x = '';
word_y = '';
for (i, j) in path:
x = X[i];
y = Y[j];
match Moves[i, j]:
case Directions.DIAGONAL:
word_x += x;
word_y += y;
case Directions.HORIZONTAL:
word_x += '-';
word_y += y;
case Directions.VERTICAL:
word_x += x;
word_y += '-';
return word_x, word_y;
def reconstruct_optimal_path(
Moves: NDArray[(Any, Any), Directions],
coord: Optional[Tuple[int, int]] = None,
) -> List[Tuple[int, int]]:
'''
Liest Matrix mit optimalen Schritten den optimalen Pfad aus,
angenfangen von Endkoordinaten.
'''
if coord is None:
m, n = Moves.shape;
(i, j) = (m-1, n-1);
else:
(i, j) = coord;
path = [(i, j)];
while (i, j) != (0, 0):
match Moves[i, j]:
case Directions.DIAGONAL:
(i, j) = (i - 1, j - 1);
case Directions.HORIZONTAL:
(i, j) = (i, j - 1);
case Directions.VERTICAL:
(i, j) = (i - 1, j);
case _:
break;
path.append((i, j));
return path[::-1];
def reconstruct_optimal_path_halves(
Costs1: NDArray[(Any, Any), int],
Costs2: NDArray[(Any, Any), int],
Moves1: NDArray[(Any, Any), Directions],
Moves2: NDArray[(Any, Any), Directions],
) -> Tuple[List[Tuple[int, int]], List[Tuple[int, int]]]:
(m, n1) = Costs1.shape;
(m, n2) = Costs2.shape;
info = [
(
Costs1[i, n1-1] + Costs2[m-1-i, n2-1],
(i, n1-1),
(m-1-i, n2-1),
)
for i in range(m)
];
index = np.argmin([ cost for cost, _, _ in info ]);
path1 = reconstruct_optimal_path(Moves1, coord=info[index][1]);
path2 = reconstruct_optimal_path(Moves2, coord=info[index][2]);
return path1, path2;
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# AUXILIARY METHODS
# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
def represent_cost_matrix(
Costs: NDArray[(Any, Any), int],
path: List[Tuple[int, int]],
X: str,
Y: str,
pad: bool = False,
) -> Tuple[NDArray[(Any, Any), Any], NDArray[(Any, Any), Any]]:
m = len(X); # display vertically
n = len(Y); # display horizontally
# erstelle string-Array:
if pad:
table = np.full(shape=(3 + m + 3, 3 + n + 1), dtype=object, fill_value='');
else:
table = np.full(shape=(3 + m, 3 + n), dtype=object, fill_value='');
# topmost rows:
table[0, 3:(3+n)] = [str(j) for j in range(n)];
table[1, 3:(3+n)] = [y for y in Y];
table[2, 3:(3+n)] = '--';
# leftmost columns:
table[3:(3+m), 0] = [str(i) for i in range(m)];
table[3:(3+m), 1] = [x for x in X];
table[3:(3+m), 2] = '|';
if pad:
table[-3, 3:(3+n)] = '--';
table[3:(3+m), -1] = '|';
table_costs = table.copy();
table_moves = table.copy();
table_costs[3:(3+m), 3:(3+n)] = Costs;
table_moves[3:(3+m), 3:(3+n)] = '.';
for (i, j) in path:
# table_costs[3 + i, 3 + j] = f'\x1b[92;1m{table_costs[3 + i, 3 + j]}\x1b[0m';
table_moves[3 + i, 3 + j] = '@';
return table_costs, table_moves;
def display_cost_matrix(
Costs: NDArray[(Any, Any), int],
path: List[Tuple[int, int]],
X: str,
Y: str,
) -> Tuple[str, str]:
'''
Zeigt Kostenmatrix + optimalen Pfad.
@inputs
- `Costs` - Kostenmatrix
- `Moves` - Kodiert die optimalen Schritte
- `X`, `Y` - Strings
@returns
- eine 'printable' Darstellung der Matrix mit den Strings X, Y + Indexes.
'''
table_costs, table_moves = represent_cost_matrix(Costs=Costs, path=path, X=X, Y=Y);
# benutze pandas-Dataframe, um schöner darzustellen:
costs_repr = pd.DataFrame(table_costs).to_string(index=False, header=False);
moves_repr = pd.DataFrame(table_moves).to_string(index=False, header=False);
return costs_repr, moves_repr;
def display_cost_matrix_halves(
Costs1: NDArray[(Any, Any), int],
Costs2: NDArray[(Any, Any), int],
path1: List[Tuple[int, int]],
path2: List[Tuple[int, int]],
X1: str,
X2: str,
Y1: str,
Y2: str,
) -> Tuple[str, str]:
'''
Zeigt Kostenmatrix + optimalen Pfad für Schritt im D & C Hirschberg-Algorithmus
@inputs
- `Costs1`, `Costs2` - Kostenmatrizen
- `Moves1`, `Moves2` - Kodiert die optimalen Schritte
- `X1`, `X2`, `Y1`, `Y2` - Strings
@returns
- eine 'printable' Darstellung der Matrix mit den Strings X, Y + Indexes.
'''
table_costs1, table_moves1 = represent_cost_matrix(Costs=Costs1, path=path1, X=X1, Y=Y1, pad=True);
table_costs2, table_moves2 = represent_cost_matrix(Costs=Costs2, path=path2, X=X2, Y=Y2, pad=True);
# merge Taellen:
table_costs = np.concatenate([table_costs1, table_costs2[::-1, ::-1]], axis=1);
table_moves = np.concatenate([table_moves1, table_moves2[::-1, ::-1]], axis=1);
# benutze pandas-Dataframe, um schöner darzustellen:
costs_repr = pd.DataFrame(table_costs).to_string(index=False, header=False);
moves_repr = pd.DataFrame(table_moves).to_string(index=False, header=False);
return costs_repr, moves_repr;