180 lines
3.8 KiB
Python
180 lines
3.8 KiB
Python
#!/usr/bin/python
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# -*- coding: utf-8 -*-
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from mpmath import mp
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from mpmath import libmp
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xrange = libmp.backend.xrange
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def run_hessenberg(A, verbose = 0):
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if verbose > 1:
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print("original matrix (hessenberg):\n", A)
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n = A.rows
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Q, H = mp.hessenberg(A)
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if verbose > 1:
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print("Q:\n",Q)
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print("H:\n",H)
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B = Q * H * Q.transpose_conj()
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eps = mp.exp(0.8 * mp.log(mp.eps))
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err0 = 0
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for x in xrange(n):
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for y in xrange(n):
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err0 += abs(A[y,x] - B[y,x])
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err0 /= n * n
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err1 = 0
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for x in xrange(n):
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for y in xrange(x + 2, n):
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err1 += abs(H[y,x])
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if verbose > 0:
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print("difference (H):", err0, err1)
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if verbose > 1:
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print("B:\n", B)
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assert err0 < eps
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assert err1 == 0
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def run_schur(A, verbose = 0):
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if verbose > 1:
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print("original matrix (schur):\n", A)
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n = A.rows
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Q, R = mp.schur(A)
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if verbose > 1:
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print("Q:\n", Q)
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print("R:\n", R)
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B = Q * R * Q.transpose_conj()
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C = Q * Q.transpose_conj()
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eps = mp.exp(0.8 * mp.log(mp.eps))
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err0 = 0
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for x in xrange(n):
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for y in xrange(n):
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err0 += abs(A[y,x] - B[y,x])
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err0 /= n * n
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err1 = 0
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for x in xrange(n):
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for y in xrange(n):
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if x == y:
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C[y,x] -= 1
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err1 += abs(C[y,x])
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err1 /= n * n
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err2 = 0
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for x in xrange(n):
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for y in xrange(x + 1, n):
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err2 += abs(R[y,x])
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if verbose > 0:
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print("difference (S):", err0, err1, err2)
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if verbose > 1:
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print("B:\n", B)
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assert err0 < eps
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assert err1 < eps
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assert err2 == 0
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def run_eig(A, verbose = 0):
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if verbose > 1:
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print("original matrix (eig):\n", A)
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n = A.rows
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E, EL, ER = mp.eig(A, left = True, right = True)
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if verbose > 1:
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print("E:\n", E)
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print("EL:\n", EL)
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print("ER:\n", ER)
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eps = mp.exp(0.8 * mp.log(mp.eps))
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err0 = 0
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for i in xrange(n):
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B = A * ER[:,i] - E[i] * ER[:,i]
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err0 = max(err0, mp.mnorm(B))
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B = EL[i,:] * A - EL[i,:] * E[i]
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err0 = max(err0, mp.mnorm(B))
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err0 /= n * n
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if verbose > 0:
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print("difference (E):", err0)
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assert err0 < eps
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#####################
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def test_eig_dyn():
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v = 0
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for i in xrange(5):
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n = 1 + int(mp.rand() * 5)
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if mp.rand() > 0.5:
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# real
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A = 2 * mp.randmatrix(n, n) - 1
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if mp.rand() > 0.5:
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A *= 10
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for x in xrange(n):
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for y in xrange(n):
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A[x,y] = int(A[x,y])
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else:
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A = (2 * mp.randmatrix(n, n) - 1) + 1j * (2 * mp.randmatrix(n, n) - 1)
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if mp.rand() > 0.5:
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A *= 10
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for x in xrange(n):
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for y in xrange(n):
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A[x,y] = int(mp.re(A[x,y])) + 1j * int(mp.im(A[x,y]))
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run_hessenberg(A, verbose = v)
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run_schur(A, verbose = v)
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run_eig(A, verbose = v)
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def test_eig():
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v = 0
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AS = []
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A = mp.matrix([[2, 1, 0], # jordan block of size 3
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[0, 2, 1],
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[0, 0, 2]])
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AS.append(A)
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AS.append(A.transpose())
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A = mp.matrix([[2, 0, 0], # jordan block of size 2
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[0, 2, 1],
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[0, 0, 2]])
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AS.append(A)
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AS.append(A.transpose())
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A = mp.matrix([[2, 0, 1], # jordan block of size 2
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[0, 2, 0],
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[0, 0, 2]])
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AS.append(A)
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AS.append(A.transpose())
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A= mp.matrix([[0, 0, 1], # cyclic
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[1, 0, 0],
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[0, 1, 0]])
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AS.append(A)
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AS.append(A.transpose())
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for A in AS:
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run_hessenberg(A, verbose = v)
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run_schur(A, verbose = v)
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run_eig(A, verbose = v)
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