test_arrayutils.py

import time
import math
import array

from emlearn_arrayutils import linear_map

# unequal lengths, should raise
# unsupported source array type, should raise
# unsupported target array type

def assert_almost_equal(a, b, rtol=0.001, errortol=0):
    if len(a) != len(b):
        assert False, (len(a), len(b))

    errors = 0
    for x, y in zip(a, b):
        rdiff = abs((x - y) / (y+0.00001))
        if rdiff > rtol:
            errors += 1

    assert errors <= errortol, (errors)


def test_arrayutils_linear_map_float_int16():

    length = 2000
    int16 = array.array('h', (i-length//2 for i in range(length)))
    flt = array.array('f', (0 for _ in range(length)))
    out = array.array('h', (0 for _ in range(length)))

    # roundtrip should be (approx) equal
    start = time.ticks_us()
    linear_map(int16, flt, -2**15, 2**15, -1.0, 1.0)
    linear_map(flt, out, -1.0, 1.0, -2**15, 2**15)
    d = time.ticks_diff(time.ticks_us(), start)
    print('linear_map int16>float>int16', length, d/1000.0)
    assert_almost_equal(out, int16)

if __name__ == '__main__':
    test_arrayutils_linear_map_float_int16()

# Other functionality
# reinterpret
# incorrect lengths, should raise
# roundtrip should be approx equal
# bytearray <-> int16 LE / BE

# initialize filled
#arr = make_filled(length, value)
#length should be correct
#each element should be equal to value