def distance(phi, dx=1.0, self_test=False, order=2, ignore_mask=None):
"""
Return the distance from the zero contour of the array phi.
Parameters
----------
phi : array-like
the zero contour of this array is the boundary location for
the distance calculation. Phi can of 1,2,3 or higher
dimension and can be a masked array.
dx : float or an array-like of shape len(phi), optional
the cell length in each dimension.
self_test : bool, optional
if True consistency checks are made on the binary min
heap during the calculation. This is used in testing and
results in a slower calculation.
order : int, optional
order of computational stencil to use in updating points during
the fast marching method. Must be 1 or 2, the default is 2.
Returns
-------
d : an array the same shape as phi
contains the distance from the zero contour (zero level set)
of phi to each point in the array.
"""
phi, dx, flag, ext_mask = pre_process_args(phi, dx)
d = cFastMarcher(phi, dx, flag, ignore_mask, None, ext_mask, int(self_test), DISTANCE, order)
d = post_process_result(d)
# if ignore_mask is not None:
# return distance(d, dx, self_test, order)
return d
def extension_velocities(phi, speed, dx=1.0, self_test=False, order=2, ext_mask=None):
"""
Extend the velocities defined at the zero contour of phi to the
rest of the domain. Extend the velocities such that
grad f_ext dot grad d = 0 where where f_ext is the
extension velocity and d is the signed distance function.
Parameters
----------
phi : array-like
the zero contour of this array is the boundary location for
the travel time calculation. Phi can of 1,2,3 or higher
dimension and can be a masked array.
speed : array-like, the same shape as phi
contains the speed of interface propagation at each point
in the domain.
dx : float or an array-like of shape len(phi), optional
the cell length in each dimension.
self_test : bool, optional
if True consistency checks are made on the binary min
heap during the calculation. This is used in testing and
results in a slower calculation.
order : int, optional
order of computational stencil to use in updating points during
the fast marching method. Must be 1 or 2, the default is 2.
ext_mask : array-like, the same shape as phi, optional
enables initial front values to be eliminated when
calculating the value at the interface before the
values are extended away from the interface.
Returns
-------
(d, f_ext) : tuple
a tuple containing the signed distance function d and the
extension velocities f_ext.
"""
phi, dx, flag, ext_mask = pre_process_args(phi, dx, ext_mask)
distance, f_ext = cFastMarcher(phi, dx, flag, None, speed, ext_mask,
int(self_test), EXTENSION_VELOCITY, order)
distance = post_process_result(distance)
f_ext = post_process_result(f_ext)
return distance, f_ext
def extension_velocities(phi, speed, dx=1.0, self_test=False, order=2, ext_mask=None):
"""
Extend the velocities defined at the zero contour of phi to the
rest of the domain. Extend the velocities such that
grad f_ext dot grad d = 0 where where f_ext is the
extension velocity and d is the signed distance function.
Parameters
----------
phi : array-like
the zero contour of this array is the boundary location for
the travel time calculation. Phi can of 1,2,3 or higher
dimension and can be a masked array.
speed : array-like, the same shape as phi
contains the speed of interface propagation at each point
in the domain.
dx : float or an array-like of shape len(phi), optional
the cell length in each dimension.
self_test : bool, optional
if True consistency checks are made on the binary min
heap during the calculation. This is used in testing and
results in a slower calculation.
order : int, optional
order of computational stencil to use in updating points during
the fast marching method. Must be 1 or 2, the default is 2.
ext_mask : array-like, the same shape as phi, optional
enables initial front values to be eliminated when
calculating the value at the interface before the
values are extended away from the interface.
Returns
-------
(d, f_ext) : tuple
a tuple containing the signed distance function d and the
extension velocities f_ext.
"""
phi, dx, flag, ext_mask = pre_process_args(phi, dx, ext_mask)
distance, f_ext = cFastMarcher(phi, dx, flag, None, speed, ext_mask, int(self_test), EXTENSION_VELOCITY, order)
distance = post_process_result(distance)
f_ext = post_process_result(f_ext)
return distance, f_ext
def travel_time(phi, speed, dx=1.0, self_test=False, order=2):
"""
Return the travel from the zero contour of the array phi given the
scalar velocity field speed.
Parameters
----------
phi : array-like
the zero contour of this array is the boundary location for
the travel time calculation. Phi can of 1,2,3 or higher
dimension and can be a masked array.
speed : array-like, the same shape as phi
contains the speed of interface propagation at each point
in the domain.
dx : float or an array-like of shape len(phi), optional
the cell length in each dimension.
self_test : bool, optional
if True consistency checks are made on the binary min
heap during the calculation. This is used in testing and
results in a slower calculation.
order : int, optional
order of computational stencil to use in updating points during
the fast marching method. Must be 1 or 2, the default is 2.
Returns
-------
t : an array the same shape as phi
contains the travel time from the zero contour (zero level
set) of phi to each point in the array given the scalar
velocity field speed. If the input array speed has values less
than or equal to zero the return value will be a masked array.
"""
phi, dx, flag, ext_mask = pre_process_args(phi, dx)
t = cFastMarcher(phi, dx, flag, None, speed, ext_mask,
int(self_test), TRAVEL_TIME, order)
t = post_process_result(t)
return t
def travel_time(phi, speed, dx=1.0, self_test=False, order=2):
"""
Return the travel from the zero contour of the array phi given the
scalar velocity field speed.
Parameters
----------
phi : array-like
the zero contour of this array is the boundary location for
the travel time calculation. Phi can of 1,2,3 or higher
dimension and can be a masked array.
speed : array-like, the same shape as phi
contains the speed of interface propagation at each point
in the domain.
dx : float or an array-like of shape len(phi), optional
the cell length in each dimension.
self_test : bool, optional
if True consistency checks are made on the binary min
heap during the calculation. This is used in testing and
results in a slower calculation.
order : int, optional
order of computational stencil to use in updating points during
the fast marching method. Must be 1 or 2, the default is 2.
Returns
-------
t : an array the same shape as phi
contains the travel time from the zero contour (zero level
set) of phi to each point in the array given the scalar
velocity field speed. If the input array speed has values less
than or equal to zero the return value will be a masked array.
"""
phi, dx, flag, ext_mask = pre_process_args(phi, dx)
t = cFastMarcher(phi, dx, flag, None, speed, ext_mask, int(self_test), TRAVEL_TIME, order)
t = post_process_result(t)
return t
def distance(phi, dx=1.0, self_test=False, order=2, ignore_mask=None):
"""
Return the distance from the zero contour of the array phi.
Parameters
----------
phi : array-like
the zero contour of this array is the boundary location for
the distance calculation. Phi can of 1,2,3 or higher
dimension and can be a masked array.
dx : float or an array-like of shape len(phi), optional
the cell length in each dimension.
self_test : bool, optional
if True consistency checks are made on the binary min
heap during the calculation. This is used in testing and
results in a slower calculation.
order : int, optional
order of computational stencil to use in updating points during
the fast marching method. Must be 1 or 2, the default is 2.
Returns
-------
d : an array the same shape as phi
contains the distance from the zero contour (zero level set)
of phi to each point in the array.
"""
phi, dx, flag, ext_mask = pre_process_args(phi, dx)
d = cFastMarcher(phi, dx, flag, ignore_mask, None, ext_mask,
int(self_test), DISTANCE, order)
d = post_process_result(d)
# if ignore_mask is not None:
# return distance(d, dx, self_test, order)
return d
