Finding local maxima/minima with Numpy in a 1D numpy array

Question

Can you suggest a module function from numpy/scipy that can find local maxima/minima in a 1D numpy array? Obviously the simplest approach ever is to have a look at the neare

Answer 1

None of these solutions worked for me since I wanted to find peaks in the center of repeating values as well. for example, in

ar = np.array([0,1,2,2,2,1,3,3,3,2,5,0])

the answer should be

array([ 3,  7, 10], dtype=int64)

I did this using a loop. I know it's not super clean, but it gets the job done.

def findLocalMaxima(ar):
# find local maxima of array, including centers of repeating elements    
maxInd = np.zeros_like(ar)
peakVar = -np.inf
i = -1
while i < len(ar)-1:
#for i in range(len(ar)):
    i += 1
    if peakVar < ar[i]:
        peakVar = ar[i]
        for j in range(i,len(ar)):
            if peakVar < ar[j]:
                break
            elif peakVar == ar[j]:
                continue
            elif peakVar > ar[j]:
                peakInd = i + np.floor(abs(i-j)/2)
                maxInd[peakInd.astype(int)] = 1
                i = j
                break
    peakVar = ar[i]
maxInd = np.where(maxInd)[0]
return maxInd