def cp1c21():
a = np.array([[2.0, -2.0, -1.0, -2.0], [4.0, 1.0, -2.0, 1.0],
[-2.0, 1.0, -1.0, -3.0]])
b = np.array([[1.0, 2.0, -1.0, 2], [0, 3.0, 1.0, 4], [2.0, -1.0, 1.0, 2]])
c = np.array([[2.0, 1.0, -4.0, -7], [1, -1.0, 1.0, -2],
[-1.0, 3.0, -2.0, 6]])
ag = gausselim(a)[0]
bg = gausselim(b)[0]
cg = gausselim(c)[0]
print("Oppgave A")
print(ag)
s1 = tilbakesubstitusjon(ag)
print(s1)
print()
print("Oppgave B")
print(bg)
s2 = tilbakesubstitusjon(bg)
print(s2)
print()
print("Oppgave C")
print(cg)
s3 = tilbakesubstitusjon(cg)
print(s3)
def cp6c23():
oppg62 = np.array([[10.0**-20, 1.0, 1.0], [1.0, 2.0, 4.0]])
oppg63 = np.array([[1.0, 2.0, 4.0], [10.0**-20, 1.0, 1.0]])
print("Naiv gauss")
print(tilbakesubstitusjon(gausselim(oppg62)[0]))
print("Med radbytte")
print(tilbakesubstitusjon(gausselim(oppg63)[0]))
def cp1c22(arr):
A = arr
U = gausselim(A)[0]
L = gausselim(A)[1]
print("L:")
print(L)
print("U:")
print(U)
def cp2c22(A):
s = A.shape
L = gausselim(A)[1]
L = np.c_[L, A[:, s[1] - 1]]
U = gausselim(A)[0]
x1 = LUtilbakesubstitusjon(L)
U = np.c_[U, x1]
print(tilbakesubstitusjon(U))
def cp2c21(n):
A = 1. / (np.arange(1, n + 1) + np.arange(0, n)[:, np.newaxis])
A = np.c_[A, np.ones(n)]
B = gausselim(A)[0]
S = tilbakesubstitusjon(B)
print(S)