def filter_none_from_frequency_count(frequency_count):
"""
Filter out None rows from a frequency count.
A frequency count is a list of tuples or a list of lists, in which the first
element is the property, and the second element is the count.
Parameters
----------
frequency_count: list of lists or tuples with length 2
Returns
-------
new_frequency_count: list of lists or tuples with length 2
Example
-------
>> a = [ [None, 4], [1, 2], [2, 3], [10, 1] ]
>> UtilsContainer.filter_none_from_frequency_count(a)
[ [1, 2], [2, 3], [10, 1] ]
>> a = [ [None, 4], ['None', 2], ['c', 3], ['d', 1] ]
>> UtilsContainer.filter_none_from_frequency_count(a)
[ ['None', 2], ['c', 3], ['d', 1] ]
"""
Assert.frequency_count(frequency_count)
new_frequency_count = [x for x in frequency_count if x[0] is not None]
return new_frequency_count
def frequency_count2occurrence_list(frequency_count):
"""Transform a frequency count into an occurrence list.
A frequency count is a list of tuples or a list of lists, in which the first
element is the property, and the second element is the count. An occurrence
list is a list with each property <count> times in it.
Parameters
----------
frequency_count: list of lists or tuples with length 2
Returns
-------
occurrence_list: np.array, dtype = <type(most general key in frequency_count)>
Example
-------
>> a = [ [0, 4], [1, 2], [2, 3], [10, 1] ]
>> UtilsContainer.frequency_count2occurrence_list(a)
[ 0 0 0 0 1 1 2 2 2 10]
>> a = [ ['a', 4], ['b', 2], ['c', 3], ['d', 1] ]
>> UtilsContainer.frequency_count2occurrence_list(a)
['a' 'a' 'a' 'a' 'b' 'b' 'c' 'c' 'c' 'd']
"""
Assert.frequency_count(frequency_count)
occurrence_list = np.empty(0)
for k, v in frequency_count:
if k is not None:
k_list = np.empty(v, dtype=type(k))
k_list.fill(k)
occurrence_list = np.append(occurrence_list, k_list)
return occurrence_list
