sosokker/Calculator-for-Matrix-and-Algebra
1
0
Fork 0
mirror of https://github.com/Sosokker/Calculator-for-Matrix-and-Algebra.git synced 2025-12-18 12:44:05 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity

Fix determinant finding func

Browse Source
This commit is contained in:
Sirin Puenggun 2022-12-05 16:49:25 +07:00
parent dfdf7326a9
commit 25e7a3d098
1 changed files with 18 additions and 55 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
nessesary/matrix.py
View File

@ -78,65 +78,33 @@ class Matrix:
def determinant(self):
"""
Using Cofactor Expanion.
|M| = sum[M(1,i)*Cofactor(M(1,i)) from i = 1 to n]
Find determinant of Square Matrix
>>> m1 = Matrix([[1,2,3],[1,2,3],[1,2,3]])
>>> d = m1.determinant()
>>> d
>>> m1.determinant()
0
>>> m2 = Matrix([[13212,1,3,8321],[27,2,4,6],[321,5,2,-14],[312,21,211,3]])
>>> m2.determinant()
858575226
"""
if self.row != self.column:
raise ValueError(f"Can't Find determinant of {self.row} x {self.column} Matrix")
if self.row == 2 and self.column == 2:
if len(self.array) == 2 and len(self.array[0]) == 2:
return self.array[0][0] * self.array[1][1] - self.array[1][0] * self.array[0][1]
# value = 0
# index_cut_column = [range(self.row)]
# for column_to_cut in index_cut_column:
# temp_matrix = self.copy_matrix()
# temp_matrix.array = temp_matrix.array[1:]
# row_count = len(temp_matrix.array)
# for row_index in range(row_count):
# temp_matrix.array[row_index] = temp_matrix.array[row_index][0:column_to_cut] + temp_matrix.array[row_index][column_to_cut+1:]
# coeff_sign = (-1) ** (column_to_cut % 2)
# sub_determinant = temp_matrix.determinant()
# value = coeff_sign * self.array[0][column_to_cut] * sub_determinant
value = 0
for x in range(0, self.row):
i = 0
j = x
det = 0
for col in range(self.column):
temp = self.copy_matrix()
temp.array = temp.array[1:]
for r in range(len(temp.array)):
temp.array[r] = temp.array[r][0:col] + temp.array[r][col+1:]
sum_mul = 1
for y in range(0, self.row):
sum_mul *= self.array[i][j]
i += 1
j += 1
if (j >= self.row):
j = 0
value += sum_mul
sum_sub = 0
for x in range(0, self.row):
i = 0
j = self.row - 1 - x
sum_mul = 1
for y in range(0, self.row):
sum_mul *= self.array[i][j]
i += 1
j -= 1
if (j < 0):
j = self.row - 1
sum_sub -= sum_mul
determinant = value + sum_sub
return determinant
det += (-1)**(col) * self.array[0][col] * temp.determinant()
return det
def tranpose(self):
"""
@ -162,9 +130,4 @@ if __name__ == "__main__":
import doctest
doctest.testmod()
# Use the following line INSTEAD if you want to print all tests anyway.
# doctest.testmod(verbose = True)
m1 = Matrix([[1,1,1],[2,2,2],[3,3,3]])
d = m1.determinant()
print(d)
# doctest.testmod(verbose = True)