Linearly and maximally spaced values from an array

spaced.py

def linspaced_in_range(arr, n, return_indices=False, return_reverse_indices=False):
    """ Return n values spaced linearly from within arr """
    i = np.linspace(0, arr.size - 1, n, dtype=int)
    spaced = np.sort(arr)[i]
    spaced_i = np.argsort(arr)[i]
    spaced_ri = np.array(list(set(np.arange(arr.size)) - set(spaced_i)))
    ret = [spaced]
    if return_indices:
        ret.append(spaced_i)
    if return_reverse_indices:
        ret.append(spaced_ri)
    if len(ret) == 1:
        ret = ret[0]
    return ret
 
def maxspaced_in_range(arr, n, return_indices=False, return_reverse_indices=False):
    """ Return n values maximally spaced from within arr """
    if n > arr.size:
        raise ValueError(f"arr has size {arr.size}, but trying to get {n} values")
    step1 = step2 = n // 2
    step1 += 1 if (n % 2 != 0) else 0 # for odd n, take one extra value from the "bottom"
    sorted = np.sort(arr)
    spaced = np.r_[sorted[:step1], sorted[-step2:]]
    arg_sorted = np.argsort(arr)
    spaced_i = np.r_[arg_sorted[:step1], arg_sorted[-step2:]]
    spaced_ri = np.array(list(set(np.arange(arr.size)) - set(spaced_i)))
    ret = [spaced]
    if return_indices:
        ret.append(spaced_i)
    if return_reverse_indices:
        ret.append(spaced_ri)
    if len(ret) == 1:
        ret = ret[0]
    return spaced