How to detect the peak Values using Python SciPy, getting index error"arrays used as indices must be of integer (or boolean) type"

Question

I have the speed data in that I need to detect the values where threshold is greater than 20 and valley greater than 0. I used this code for peak detection but I am getting index error

import numpy as np
from scipy.signal import find_peaks, find_peaks_cwt
import matplotlib.pyplot as plt
import pandas as pd
import sys
np.set_printoptions(threshold=sys.maxsize)
zero_locs = np.where(x==0)
search_lims = np.append(zero_locs, len(x)) # limits for search area

diff_x = np.diff(x)
diff_x_mapped = diff_x > 0
peak_locs = []
x = np.array([1, 9, 18, 24, 26, 5, 26, 25, 26, 16, 20, 16, 23, 5, 1, 27, 
22, 26, 27, 26, 25, 24, 25, 26, 3, 25, 26, 24, 23, 12, 22, 11, 15, 24, 11, 
26, 26, 26, 24, 25, 24, 24, 22, 22, 22, 23, 24])

for i in range(len(search_lims)-1):
    peak_loc = search_lims[i] + np.where(diff_x_mapped[search_lims[i]:search_lims[i+1]]==0)[0][0]
    if x[peak_loc] > 20:
        peak_locs.append(peak_loc)
fig= plt.figure(figsize=(10,4))
plt.plot(x)
plt.plot(np.array(peak_locs), x[np.array(peak_locs)], "x", color = 'r')

I tried using peak detection algorithm where it is not detecting peaks where the peak value is above 20 i need to detect the peaks where x values is 0 and peak values is 20 expected output: the marked peaks has to be detected by running the above script i am getting this error

IndexError: arrays used as indices must be of integer (or boolean) type

how to get ride of this error any suggestions thanks in regards

Answer 1

You found no peaks. That is, len(peak_locs) is zero.

So you wind up with this array, whose type defaulted to float:

>>> np.array(peak_locs)
array([], dtype=float64)

To fix it? Find more peaks!