def idd_snorm(m, n, matvect, matvec, its=20):
"""
Estimate spectral norm of a real matrix by the randomized power method.
:param m:
Matrix row dimension.
:type m: int
:param n:
Matrix column dimension.
:type n: int
:param matvect:
Function to apply the matrix transpose to a vector, with call signature
`y = matvect(x)`, where `x` and `y` are the input and output vectors,
respectively.
:type matvect: function
:param matvec:
Function to apply the matrix to a vector, with call signature
`y = matvec(x)`, where `x` and `y` are the input and output vectors,
respectively.
:type matvec: function
:param its:
Number of power method iterations.
:type its: int
:return:
Spectral norm estimate.
:rtype: float
"""
snorm, v = _id.idd_snorm(m, n, matvect, matvec, its)
return snorm
def idd_snorm(m, n, matvect, matvec, its=20):
"""
Estimate spectral norm of a real matrix by the randomized power method.
:param m:
Matrix row dimension.
:type m: int
:param n:
Matrix column dimension.
:type n: int
:param matvect:
Function to apply the matrix transpose to a vector, with call signature
`y = matvect(x)`, where `x` and `y` are the input and output vectors,
respectively.
:type matvect: function
:param matvec:
Function to apply the matrix to a vector, with call signature
`y = matvec(x)`, where `x` and `y` are the input and output vectors,
respectively.
:type matvec: function
:param its:
Number of power method iterations.
:type its: int
:return:
Spectral norm estimate.
:rtype: float
"""
snorm, v = _id.idd_snorm(m, n, matvect, matvec, its)
return snorm