Example #1
0
File: expm.py Project: qqchen/pyla
 def calculate_expm(t):
     num = zeros(n, n)
     den = zeros(n, n)
     s = 1
     k = context.one  # t^n is stored here
     for m_i, ai in m_a_list:
         aik = ai * k
         mat_combine_inplace(num, m_i, aik)
         mat_combine_inplace(den, m_i, s * aik)
         s = -s
         k *= t
     return solve(den, num)
Example #2
0
File: expm.py Project: Rambood/pyla
 def calculate_expm(t):
     num = zeros(n,n)
     den = zeros(n,n)
     s = 1
     k = context.one # t^n is stored here
     for m_i, ai in m_a_list:
         aik = ai*k
         mat_combine_inplace( num, m_i, aik )
         mat_combine_inplace( den, m_i, s*aik)
         s = -s
         k *= t
     return solve( den, num )
Example #3
0
File: expm.py Project: qqchen/pyla
def expm(m, context=FloatContext, order=7):
    """Matrix exponent, using Pade approximation of given order
    """
    a = _exp_pade_coeffs(order)
    n, n_ = shape_mat(m)
    assert (n == n_)

    num = zeros(n, n)
    den = zeros(n, n)

    s = 1
    for m_i, ai in izip(matrix_powers(m), a):
        mat_combine_inplace(num, m_i, ai)
        mat_combine_inplace(den, m_i, s * ai)
        s = -s

    return solve(den, num)
Example #4
0
File: expm.py Project: Rambood/pyla
def expm( m, context=FloatContext, order=7 ):
    """Matrix exponent, using Pade approximation of given order
    """
    a = _exp_pade_coeffs( order )
    n,n_ = shape_mat( m )
    assert( n == n_ )
    
    num = zeros(n,n)
    den = zeros(n,n)

    s = 1
    for m_i, ai in izip( matrix_powers(m), a ):
        mat_combine_inplace( num, m_i, ai )
        mat_combine_inplace( den, m_i, s*ai)
        s = -s

    return solve( den, num )