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Changes after dev meeting
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@MargaretDuff
MargaretDuff committed Aug 17, 2023
1 parent ba35fb8 commit beac6fa
Showing 1 changed file with 60 additions and 63 deletions.
123 changes: 60 additions & 63 deletions Wrappers/Python/cil/framework/sampler.py
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Original file line number Diff line number Diff line change
Expand Up @@ -55,8 +55,8 @@ class Sampler():
-------
>>> sampler=Sampler.sequential(10)
>>> sampler.show_epochs(5)
>>> for _ in range(11):
>>> sampler.show_samples(5)
>>> for _ in range(55):
print(sampler.next())
Epoch 0: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Expand All @@ -82,25 +82,22 @@ class Sampler():
>>> sampler=Sampler.randomWithReplacement(11)
>>> for _ in range(12):
>>> print(next(sampler))
>>> sampler.show_epochs(5)
>>> sampler.show_samples(54)
10
5
10
1
6
7
10
0
0
2
5
3
Epoch 0: [10, 5, 10, 1, 6, 7, 10, 0, 0, 2, 5]
Epoch 1: [3, 10, 7, 7, 8, 7, 4, 7, 8, 4, 9]
Epoch 2: [0, 0, 0, 1, 3, 8, 6, 5, 7, 7, 0]
Epoch 3: [8, 8, 6, 4, 0, 2, 7, 2, 8, 3, 8]
Epoch 4: [10, 9, 3, 6, 6, 9, 5, 2, 8, 4, 0]
3
2
0
3
3
1
2
1
1
The first 54 samples: [0, 2, 3, 3, 2, 0, 3, 3, 1, 2, 1, 1, 2, 3, 3, 1, 3, 2, 4, 0, 0, 0, 1, 1, 3, 0, 4, 3, 3, 3, 0, 0, 0, 2, 4, 0, 1, 2, 3, 4, 0, 4, 4, 1, 4, 1, 4, 3, 0, 2, 3, 0, 1, 4]
Expand All @@ -118,15 +115,15 @@ def sequential(num_subsets):
-------
>>> sampler=Sampler.sequential(10)
>>> sampler.show_epochs(5)
>>> sampler.show_samples(49)
>>> for _ in range(11):
print(sampler.next())
Epoch 0: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Epoch 1: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Epoch 2: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Epoch 3: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Epoch 4: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
Epoch 4: [0, 1, 2, 3, 4, 5, 6, 7, 8]
0
1
2
Expand Down Expand Up @@ -156,13 +153,10 @@ def customOrder( customlist):
--------
>>> sampler=Sampler.customOrder([1,4,6,7,8,9,11])
>>> sampler.show_epochs(5)
>>> sampler.show_samples(11)
Epoch 0: [1, 4, 6, 7, 8, 9, 11]
Epoch 1: [1, 4, 6, 7, 8, 9, 11]
Epoch 2: [1, 4, 6, 7, 8, 9, 11]
Epoch 3: [1, 4, 6, 7, 8, 9, 11]
Epoch 4: [1, 4, 6, 7, 8, 9, 11]
Epoch 1: [1, 4, 6, 7]
"""
num_subsets=len(customlist)
Expand All @@ -175,7 +169,7 @@ def hermanMeyer(num_subsets):
Function that takes a number of subsets and returns a sampler which outputs a Herman Meyer order
num_subsets: int
The sampler will select from a list of integers {0, 1, …, S-1} with S=num_subsets.
The sampler will select from a list of integers {0, 1, …, S-1} with S=num_subsets. For Herman-Meyer sampling this number should not be prime.
Reference
----------
Expand All @@ -184,7 +178,7 @@ def hermanMeyer(num_subsets):
Example
-------
>>> sampler=Sampler.hermanMeyer(12)
>>> sampler.show_epochs(5)
>>> sampler.show_samples(60)
Epoch 0: [0, 6, 3, 9, 1, 7, 4, 10, 2, 8, 5, 11]
Epoch 1: [0, 6, 3, 9, 1, 7, 4, 10, 2, 8, 5, 11]
Expand All @@ -206,6 +200,8 @@ def _herman_meyer_order(n):
if n_variable > 1:
factors.append(n_variable)
n_factors = len(factors)
if n_factors==0:
raise ValueError('Herman Meyer sampling defaults to sequential ordering if the number of subsets is prime. Please use an alternative sampling method or change the number of subsets. ')
order = [0 for _ in range(n)]
value = 0
for factor_n in range(n_factors):
Expand Down Expand Up @@ -240,20 +236,21 @@ def staggered(num_subsets, offset):
offset: int
The sampler will output in the order {0, a, 2a, 3a, ...., 1, 1+a, 1+2a, 1+3a,...., 2, 2+a, 2+2a, 2+3a,...} where a=offset.
The offset should be less than the num_subsets
Example
-------
>>> sampler=Sampler.staggered(20,4)
>>> sampler.show_epochs(5)
>>> sampler.show_samples(100)
Epoch 0: [0, 4, 8, 12, 16, 1, 5, 9, 13, 17, 2, 6, 10, 14, 18, 3, 7, 11, 15, 19]
Epoch 1: [0, 4, 8, 12, 16, 1, 5, 9, 13, 17, 2, 6, 10, 14, 18, 3, 7, 11, 15, 19]
Epoch 2: [0, 4, 8, 12, 16, 1, 5, 9, 13, 17, 2, 6, 10, 14, 18, 3, 7, 11, 15, 19]
Epoch 3: [0, 4, 8, 12, 16, 1, 5, 9, 13, 17, 2, 6, 10, 14, 18, 3, 7, 11, 15, 19]
Epoch 4: [0, 4, 8, 12, 16, 1, 5, 9, 13, 17, 2, 6, 10, 14, 18, 3, 7, 11, 15, 19]
"""

if offset>=num_subsets:
raise(ValueError('The offset should be less than the number of subsets'))
indices=list(range(num_subsets))
order=[]
[order.extend(indices[i::offset]) for i in range(offset)]
Expand Down Expand Up @@ -282,35 +279,26 @@ def randomWithReplacement(num_subsets, prob=None, seed=None):
>>> sampler=Sampler.randomWithReplacement(5)
>>> print(sampler.get_epochs())
[[3, 2, 2, 4, 4], [0, 1, 2, 4, 4]]
>>> print(sampler.get_samples(10))
The first 10 samples: [2, 1, 2, 3, 2, 1, 2, 2, 1, 2]
Example
-------
>>> sampler=Sampler.randomWithReplacement(4, [0.7,0.1,0.1,0.1])
>>> sampler.show_epochs(5)
>>> sampler.show_samples(21)
Epoch 0: [1, 0, 0, 0]
Epoch 1: [0, 0, 0, 0]
Epoch 2: [0, 0, 2, 2]
Epoch 3: [0, 0, 3, 0]
Epoch 4: [3, 2, 0, 0]
The first 21 samples: [3, 2, 0, 2, 0, 0, 0, 0, 0, 3, 0, 1, 0, 0, 2, 0, 0, 0, 1, 2, 0]
"""

if prob==None:
prob = [1/num_subsets] *num_subsets
else:
prob=prob
if len(prob)!=num_subsets:
raise ValueError("Length of the list of probabilities should equal the number of subsets")
if sum(prob)-1.>=1e-5:
raise ValueError("Probabilities should sum to 1. Your probabilities sum to {}".format(sum(prob)))
sampler=Sampler(num_subsets, sampling_type='random_with_replacement', prob=prob, seed=seed)
return sampler

@staticmethod
def randomWithoutReplacement(num_subsets, seed=None):
def randomWithoutReplacement(num_subsets, seed=None, shuffle=True):

"""
Function that takes a number of subsets and returns a sampler which outputs from a list of integers {0, 1, …, S-1} with S=num_subsets uniformly randomly without replacement.
Expand All @@ -322,11 +310,12 @@ def randomWithoutReplacement(num_subsets, seed=None):
seed:int, default=None
Random seed for the random number generator. If set to None, the seed will be set using the current time.
shuffle:boolean, default=True
If True, there is a random shuffle between each epoch, if false the same random order as the first epoch is repeated for all future epochs.
Example
-------
>>> sampler=Sampler.randomWithoutReplacement(11)
>>> sampler.show_epochs(5)
>>> sampler.show_samples(55)
Epoch 0: [10, 4, 3, 0, 2, 9, 6, 8, 7, 5, 1]
Epoch 1: [6, 0, 2, 4, 5, 7, 3, 10, 9, 8, 1]
Epoch 2: [1, 2, 7, 4, 9, 5, 6, 3, 0, 8, 10]
Expand All @@ -335,7 +324,7 @@ def randomWithoutReplacement(num_subsets, seed=None):
"""

order=list(range(num_subsets))
sampler=Sampler(num_subsets, sampling_type='random_without_replacement', order=order, shuffle=True, seed=seed)
sampler=Sampler(num_subsets, sampling_type='random_without_replacement', order=order, shuffle=shuffle, seed=seed)
return sampler


Expand Down Expand Up @@ -422,23 +411,23 @@ def __next__(self):
Allows the user to call next(sampler), to get the same result as sampler.next()"""
return(self.next())

def show_epochs(self, num_epochs=2):
def show_samples(self, num_samples=20):
"""
Function that takes an integer, num_epochs, and prints the first num_epochs epochs. Calling this function will not interrupt the random number generation, if applicable.
Function that takes an integer, num_samples, and prints the first num_samples, organised into epochs where appropriate. Calling this function will not interrupt the random number generation, if applicable.
num_epochs: int, default=2
The number of epochs to print.
num_samples: int, default=20
The number of samples to print.
Example
-------
>>> sampler=Sampler.randomWithoutReplacement(11)
>>> sampler.show_epochs(5)
>>> sampler.show_samples(50)
Epoch 0: [9, 7, 2, 8, 0, 10, 1, 5, 3, 6, 4]
Epoch 1: [6, 2, 0, 10, 5, 1, 9, 8, 7, 4, 3]
Epoch 2: [5, 10, 0, 6, 1, 4, 3, 7, 2, 8, 9]
Epoch 3: [4, 8, 3, 7, 1, 10, 5, 6, 2, 9, 0]
Epoch 4: [0, 7, 2, 6, 9, 10, 8, 3, 1, 4, 5]
Epoch 4: [0, 7, 2, 6, 9, 10]
"""
save_generator=self.generator
Expand All @@ -447,25 +436,29 @@ def show_epochs(self, num_epochs=2):
save_order=self.order
self.order=self.initial_order
self.generator=np.random.RandomState(self.seed)
for i in range(num_epochs):
print('Epoch {}: '.format(i), [self.next() for _ in range(self.num_subsets)])
if self.prob==None:
for i in range(num_samples//self.num_subsets):
print('Epoch {}: '.format(i), [self.next() for _ in range(self.num_subsets)])
print('Epoch {}: '.format(num_samples//self.num_subsets), [self.next() for _ in range(num_samples%self.num_subsets)])
else:
print('The first {} samples: '.format(num_samples), [self.next() for _ in range(num_samples)])
self.generator=save_generator
self.order=save_order
self.last_subset=save_last_subset

def get_epochs(self, num_epochs=2):
def get_samples(self, num_samples=20):
"""
Function that takes an integer, num_epochs, and returns the first num_epochs epochs in the form of a list of lists. Calling this function will not interrupt the random number generation, if applicable.
Function that takes an integer, num_samples, and returns the first num_samples, organised into epochs where appropriate, as a list of lists. Calling this function will not interrupt the random number generation, if applicable.
num_epochs: int, default=2
The number of epochs to return.
num_samples: int, default=20
The number of samples to return.
Example
-------
>>> sampler=Sampler.randomWithReplacement(5)
>>> print(sampler.get_epochs())
[[3, 2, 2, 4, 4], [0, 1, 2, 4, 4]]
>>> print(sampler.get_samples())
[[2, 4, 2, 4, 1, 3, 2, 2, 1, 2, 4, 4, 2, 3, 2, 1, 0, 4, 2, 3]]
"""
save_generator=self.generator
Expand All @@ -475,8 +468,12 @@ def get_epochs(self, num_epochs=2):
self.order=self.initial_order
self.generator=np.random.RandomState(self.seed)
output=[]
for i in range(num_epochs):
output.append( [self.next() for _ in range(self.num_subsets)])
if self.prob==None:
for i in range(num_samples//self.num_subsets):
output.append( [self.next() for _ in range(self.num_subsets)])
output.append([self.next() for _ in range(num_samples%self.num_subsets)])
else:
output.append( [self.next() for _ in range(num_samples)])
self.generator=save_generator
self.order=save_order
self.last_subset=save_last_subset
Expand Down

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