Minima maxima.py

# Pythagoras function to calculate distance between two points
def pythg(pt1, pt2):
    a_sq = (pt2[0] - pt1[0]) ** 2
    b_sq = (pt2[1] - pt1[1]) ** 2
    return sqrt(a_sq + b_sq)


# Function to calculate local minima and maxima points
def loc_min_max(points):
    loc_minima = []
    loc_maxima = []
    prev_pts = [(0, points[0]), (1, points[1])]
    for i in range(1, len(points) - 1):
        append_to = ''
        if points[i-1] > points[i] < points[i+1]:
            append_to = 'min'
        elif points[i-1] < points[i] > points[i+1]:
            append_to = 'max'
        if append_to:
            if loc_minima or loc_maxima:
                prev_distance = pythg(prev_pts[0], prev_pts[1]) * 0.5
                curr_distance = pythg(prev_pts[1], (i, points[i]))
                if curr_distance >= prev_distance:
                    prev_pts[0] = prev_pts[1]
                    prev_pts[1] = (i, points[i])
                    if append_to == 'min':
                        loc_minima.append((i, points[i]))
                    else:
                        loc_maxima.append((i, points[i]))
            else:
                prev_pts[0] = prev_pts[1]
                prev_pts[1] = (i, points[i])
                if append_to == 'min':
                    loc_minima.append((i, points[i]))
                else:
                    loc_maxima.append((i, points[i]))
                    
    return loc_minima, loc_maxima

# Store the local minima and maxima points
loc_minima, loc_maxima = loc_min_max(points)
minima_pts = np.array(loc_minima)
maxima_pts = np.array(loc_maxima)