I have an array and function and I would like the function to return a list of indices in which the difference of two consecutive elements passes a threshold.
I have:
def func (y, t=100):
for i in range(1, len(y)): #Range skips 1st element
if abs(y[i] - y[i-1]) > t:
return(i)
The problem I'm facing is that this function only returns the first index where my if statement is true. How do I get the rest of them?
There are two ways. First, yield instead of return will give you a generator:
def func (y, t=100):
for i in range(1, len(y)): #Range skips 1st element
if abs(y[i] - y[i-1]) > t:
yield(i)
Or add a list in you function:
def func (y, t=100):
output = []
for i in range(1, len(y)): #Range skips 1st element
if abs(y[i] - y[i-1]) > t:
output.append(i)
return output
With a list comprehension you can do that like:
def peak_detect(in_data, threshold=100):
return [i for i, (x, y) in enumerate(zip(in_data, in_data[1:]))
if abs(y - x) >= threshold]
data = [1, 2000, 2001, 4000]
print(peak_detect(data))
[0, 2]
def peak_detect (y_, threshold=100):
indicesList = []
for i in range(1, len(y_)): #Range skips 1st element
if abs(y[i] - y[i-1]) > threshold:
indicesList.append(i)
return(indicesList)
yield iand collect items in alist(In other words convert your function to a generator function)