diff options
Diffstat (limited to 'numpy/lib/function_base.py')
| -rw-r--r-- | numpy/lib/function_base.py | 51 |
1 files changed, 35 insertions, 16 deletions
diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py index 42ea8c7a7..804f7bef3 100644 --- a/numpy/lib/function_base.py +++ b/numpy/lib/function_base.py @@ -1487,37 +1487,44 @@ def _unwrap_dispatcher(p, discont=None, axis=None): @array_function_dispatch(_unwrap_dispatcher) -def unwrap(p, discont=pi, axis=-1): - """ - Unwrap by changing deltas between values to 2*pi complement. +# def _unwrap_dispatcher(p, discont=None, axis=None, *, min_val=None, max_val=None): +# return (p,) - Unwrap radian phase `p` by changing absolute jumps greater than - `discont` to their 2*pi complement along the given axis. +# @array_function_dispatch(_unwrap_dispatcher) +def unwrap(p, interval_size= 2*pi, discont=None, axis=-1): + """ + Unwrap by changing deltas between values to complement. + + For the default case where `interval_size= 2*pi`, `discont=pi`, + It unwraps radian phase `p` by changing absolute jumps greater + than `discont` to their 2*pi complement along the given axis. + + In general it unwrapps a signal `p` by changing absolute jumps + greater than `discont` to their `interval_size` complementary values. + Parameters ---------- p : array_like Input array. + interval_size: float, optional + size of the range over which the input wraps. discont : float, optional - Maximum discontinuity between values, default is ``pi``. + Maximum discontinuity between values, default is ``interval_size/2``. axis : int, optional Axis along which unwrap will operate, default is the last axis. - Returns ------- out : ndarray Output array. - See Also -------- rad2deg, deg2rad - Notes ----- - If the discontinuity in `p` is smaller than ``pi``, but larger than - `discont`, no unwrapping is done because taking the 2*pi complement - would only make the discontinuity larger. - + If the discontinuity in `p` is smaller than ``interval_size/2``, + but larger than `discont`, no unwrapping is done because taking + the complement would only make the discontinuity larger. Examples -------- >>> phase = np.linspace(0, np.pi, num=5) @@ -1526,16 +1533,28 @@ def unwrap(p, discont=pi, axis=-1): array([ 0. , 0.78539816, 1.57079633, 5.49778714, 6.28318531]) # may vary >>> np.unwrap(phase) array([ 0. , 0.78539816, 1.57079633, -0.78539816, 0. ]) # may vary - + >>> unwrap([0, 1, 2, -1, 0], interval_size=4) + array([0., 1., 2., 3., 4.]) + >>> unwrap([ 1, 2, 3, 4, 5, 6, 1, 2, 3], interval_size=6) + array([1., 2., 3., 4., 5., 6., 7., 8., 9.]) + >>> unwrap([2, 3, 4, 5, 2, 3, 4, 5], interval_size=4) + array([2., 3., 4., 5., 6., 7., 8., 9.]) + >>> phase_deg = np.mod(np.linspace(0,720,19), 360) - 180 + >>> unwrap(phase_deg, interval_size=360) + array([-180., -140., -100., -60., -20., 20., 60., 100., 140., + 180., 220., 260., 300., 340., 380., 420., 460., 500., + 540.]) """ + if discont is None: + discont = interval_size/2 p = asarray(p) nd = p.ndim dd = diff(p, axis=axis) slice1 = [slice(None, None)]*nd # full slices slice1[axis] = slice(1, None) slice1 = tuple(slice1) - ddmod = mod(dd + pi, 2*pi) - pi - _nx.copyto(ddmod, pi, where=(ddmod == -pi) & (dd > 0)) + ddmod = mod(dd + interval_size/2, interval_size) - interval_size/2 + _nx.copyto(ddmod, interval_size/2, where=(ddmod == -interval_size/2) & (dd > 0)) ph_correct = ddmod - dd _nx.copyto(ph_correct, 0, where=abs(dd) < discont) up = array(p, copy=True, dtype='d') |