I am trying to split an array into three new arrays using inequalities.
This will give you an idea of what I am trying to achieve:
measurement = [1, 5, 10, 13, 40, 43, 60]
for x in measurement:
if 0 < x < 6:
small = measurement
elif 6 < x < 15:
medium = measurement
else
large = measurement
Intended Output:
small = [1, 5]
medium = [10, 13]
large = [40, 43, 60]
If your array is sorted, you can do :
measurement = [1, 5, 10, 13, 40, 43, 60]
one_third = len(measurement) // 3
two_third = (2 * len(measurement)) // 3
small = measurement[:one_third]
medium = measurement[one_third : two_thirds]
large = measurement[two_thirds:]
You could easily generalize to any number of split with a loop. Not sure if you wanted explicitly those inequalities or just split with the array in three. If its the first one, my answer is not right
You can use numpy:
arr = np.array(measurement)
small = arr[(arr>0)&(arr<6)] # array([1, 5])
medium = arr[(arr>6)&(arr<15)] # array([10, 13])
large = arr[(arr>15)] # array([40, 43, 60])
You can also use dictionary:
d = {'small':[], 'medium':[], 'large':[]}
for x in measurement:
if 0 < x < 6:
d['small'].append(x)
elif 6 < x < 15:
d['medium'].append(x)
else:
d['large'].append(x)
Output:
{'small': [1, 5], 'medium': [10, 13], 'large': [40, 43, 60]}
With the bisect module you can do something along these lines:
from bisect import bisect
breaks=[0,6,15,float('inf')]
buckets={}
m = [1, 5, 10, 13, 40, 43, 60]
for e in m:
buckets.setdefault(breaks[bisect(breaks, e)], []).append(e)
You then have a dict of lists matching what you are looking for:
>>> buckets
{6: [1, 5], 15: [10, 13], inf: [40, 43, 60]}
You can also form tuples of your break points and list that will become a dict to form the sub lists:
m = [1, 5, 10, 13, 40, 43, 60]
buckets=[('small',[]), ('medium',[]), ('large',[]), ('other',[])]
breaks=[(0,6),(6,15),(15,float('inf'))]
for x in m:
buckets[
next((i for i,t in enumerate(breaks) if t[0]<=x<t[1]), -1)
][1].append(x)
>>> dict(buckets)
{'small': [1, 5], 'medium': [10, 13], 'large': [40, 43, 60], 'other': []}
measurementis the whole original list so you are assigning the whole list tosmall,medium,large. You should be adding the element that you are comparing (x) to these lists. Please check the Python documentation about lists and specificallylist.append().