Example #1
0
def compress_shape(decompressed_shape):
    """
    Returns a run-length encoded compressed shape.

    Parameters
    ----------
    decompressed_shape : ndarray
        Decompressed shape.

    Returns
    -------
    compressed_shape : Holder
        A Holder object containing the shape of the compressed shape ndarray and the compressed shape ndarray itself.
    """

    if decompressed_shape.shape[0] != 1:
        raise ValueError("input should be of shape (1,x)")
    if not isinstance(decompressed_shape, np.ndarray):
        raise TypeError("input should be of type numpy.ndarray")

    data = np.array([decompressed_shape[0][0]])
    data = np.concatenate((data, np.diff(decompressed_shape[0])))

    mask_changes = np.array([1])
    diff_as_ones = (abs(np.diff(data)) > 1e-8).astype(int)
    mask_changes = np.concatenate((mask_changes, diff_as_ones))
    vals = data[np.nonzero(mask_changes)].astype(float)
    k = np.array(np.nonzero(np.append(mask_changes, 1)))
    k = k.reshape((1, k.shape[1]))
    n = np.diff(k)[0]

    n_extra = (n - 2).astype(float)
    vals2 = np.copy(vals)
    vals2[np.where(n_extra < 0)] = np.NAN
    n_extra[np.where(n_extra < 0)] = np.NAN
    v = np.array([vals, vals2, n_extra])
    v = np.concatenate(np.hsplit(v, v.shape[1]))
    finite_vals = np.isfinite(v)
    v = v[finite_vals]
    v_abs = abs(v)
    smallest_indices = np.where(v_abs < 1e-10)
    v[smallest_indices] = 0

    compressed_shape = Holder()
    compressed_shape.num_samples = decompressed_shape.shape[1]
    compressed_shape.data = v.reshape([1, v.shape[0]])
    return compressed_shape
Example #2
0
def makeadc(kwargs):
    """
    Makes a Holder object for an ADC Event.

    Parameters
    ----------
    kwargs : dict
        Key value mappings of ADC Event parameters_params and values.

    Returns
    -------
    adc : Holder
        ADC Event.
    """

    num_samples = kwargs.get("num_samples", 0)
    system = kwargs.get("system", Opts())
    dwell = kwargs.get("dwell", 0)
    duration = kwargs.get("duration", 0)
    delay = kwargs.get("delay", 0)
    freq_offset = kwargs.get("freq_offset", 0)
    phase_offset = kwargs.get("phase_offset", 0)

    adc = Holder()
    adc.type = 'adc'
    adc.num_samples = num_samples
    adc.dwell = dwell
    adc.delay = delay
    adc.freq_offset = freq_offset
    adc.phase_offset = phase_offset
    adc.dead_time = system.adc_dead_time

    if (dwell == 0 and duration == 0) or (dwell > 0 and duration > 0):
        raise ValueError("Either dwell or duration must be defined, not both")

    if duration > 0:
        # getcontext().prec = 4
        adc.dwell = float(Decimal(duration) / Decimal(num_samples))
    adc.duration = dwell * num_samples if dwell > 0 else 0
    return adc
Example #3
0
def get_block(self, block_index):
    """
    Returns Block at position specified by block_index.

    Parameters
    ----------
    block_index : int
        Index of Block to be retrieved.

    Returns
    -------
    block : dict
        Block at position specified by block_index.
    """

    block = {}
    event_ind = self.block_events[block_index]
    if event_ind[0] > 0:
        delay = Holder()
        delay.type = 'delay'
        delay.delay = self.delay_library.data[event_ind[0]]
        block['delay'] = delay
    elif event_ind[1] > 0:
        rf = Holder()
        rf.type = 'rf'
        lib_data = self.rf_library.data[event_ind[1]]

        amplitude, mag_shape, phase_shape = lib_data[0], lib_data[1], lib_data[
            2]
        shape_data = self.shape_library.data[mag_shape]
        compressed = Holder()
        compressed.num_samples = shape_data[0][0]
        compressed.data = shape_data[0][1:]
        compressed.data = compressed.data.reshape(
            (1, compressed.data.shape[0]))
        mag = decompress_shape(compressed)
        shape_data = self.shape_library.data[phase_shape]
        compressed.num_samples = shape_data[0][0]
        compressed.data = shape_data[0][1:]
        compressed.data = compressed.data.reshape(
            (1, compressed.data.shape[0]))
        phase = decompress_shape(compressed)
        rf.signal = 1j * 2 * np.pi * phase
        rf.signal = amplitude * mag * np.exp(rf.signal)
        rf.t = [(x * self.rf_raster_time)
                for x in range(1,
                               max(mag.shape) + 1)]
        rf.t = np.reshape(rf.t, (1, len(rf.t)))
        rf.freq_offset = lib_data[3]
        rf.phase_offset = lib_data[4]
        if max(lib_data.shape) < 6:
            lib_data = np.append(lib_data, 0)
        rf.dead_time = lib_data[5]

        block['rf'] = rf
    grad_channels = ['gx', 'gy', 'gz']
    for i in range(1, len(grad_channels) + 1):
        if event_ind[2 + (i - 1)] > 0:
            grad, compressed = Holder(), Holder()
            type = self.grad_library.type[event_ind[2 + (i - 1)]]
            lib_data = self.grad_library.data[event_ind[2 + (i - 1)]]
            grad.type = 'trap' if type == 't' else 'grad'
            grad.channel = grad_channels[i - 1][1]
            if grad.type == 'grad':
                amplitude = lib_data[0]
                shape_id = lib_data[1]
                shape_data = self.shape_library.data[shape_id]
                compressed.num_samples = shape_data[0][0]
                compressed.data = np.array([shape_data[0][1:]])
                g = decompress_shape(compressed)
                grad.waveform = amplitude * g
                grad.t = np.array([[
                    x * self.grad_raster_time for x in range(1, g.size + 1)
                ]])
            else:
                grad.amplitude, grad.rise_time, grad.flat_time, grad.fall_time = [
                    lib_data[x] for x in range(4)
                ]
                grad.area = grad.amplitude * (
                    grad.flat_time + grad.rise_time / 2 + grad.fall_time / 2)
                grad.flat_area = grad.amplitude * grad.flat_time
            block[grad_channels[i - 1]] = grad

    if event_ind[5] > 0:
        lib_data = self.adc_library.data[event_ind[5]]
        if max(lib_data.shape) < 6:
            lib_data = np.append(lib_data, 0)
        adc = Holder()
        adc.num_samples, adc.dwell, adc.delay, adc.freq_offset, adc.phase_offset, adc.dead_time = [
            lib_data[x] for x in range(6)
        ]
        adc.type = 'adc'
        block['adc'] = adc
    return block