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visualdynamics.plot.sine_tracking

sine_tracking

One tone read several ways, overlaid: the level against frequency through each tracking band and detector, over the specification.

The question this view answers is how much does the reading depend on how it was taken — so every reading is drawn over the same axes, and the specification stands back in gray behind them as the reference, the way a specification stands behind its response everywhere else here.

Each reading wears a marker as well as a color. Several readings of one channel are told apart by color alone nowhere else in the package, because nowhere else are several curves of one quantity on one channel meant to be compared line for line; and a reader who cannot separate two of the palette's hues cannot read this plot by hue. So each reading also carries its own marker shape, placed at a dozen points along it (every point would bury the curve) and shown beside its name in the legend. Shapes rather than dashes: dashes here already mean a synthesis drawn over a measurement.

The level axis is linear. The sine levels are drawn in decades elsewhere, which is right for a sweep spanning a resonance; here the readings sit within tens of percent of each other, and on a log axis the 30 % a harmonic adds to a peak reading is a sliver.

Functions:

Name Description
build_sine_tracking

Draw the readings of one channel, and return how many drew.

Functions:

build_sine_tracking 

build_sine_tracking(layout: Any, levels: Sequence[Any], settings: Sequence[Any], *, channel: int = 0, specification: Any = None, unit_system: Any = None, theme: Any = None) -> int

Draw the readings of one channel, and return how many drew.

levels and settings are what core.sine_tracking.track_sine takes and returns, in the same order; channel is the row of the levels drawn. With specification, the tone's target at that channel is drawn behind them in the specification's gray.

Source code in src/visualdynamics/plot/sine_tracking.py 
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def build_sine_tracking(layout: Any, levels: Sequence[Any],
                        settings: Sequence[Any], *, channel: int = 0,
                        specification: Any = None,
                        unit_system: Any = None, theme: Any = None) -> int:
    """Draw the readings of one channel, and return how many drew.

    `levels` and `settings` are what `core.sine_tracking.track_sine`
    takes and returns, in the same order; `channel` is the row of the
    levels drawn. With `specification`, the tone's target at that
    channel is drawn behind them in the specification's gray.
    """
    import pyqtgraph as pg

    from ..theme import theme as resolve_theme
    from ..units import DEFAULT_SYSTEM
    from . import STOOD_BACK_WIDTH, axis_label, curve_color, legend_below

    if len(levels) != len(settings):
        raise ValueError(f'{len(levels)} levels for {len(settings)} '
                         'settings; they are read and named in pairs')
    if not levels:
        raise ValueError('no readings to draw')
    colors = resolve_theme(theme)
    us = DEFAULT_SYSTEM if unit_system is None else unit_system
    first = levels[0]
    dof = first.response_dof[channel]
    dimension = first.ordinate_dim[channel]

    plot = layout.addPlot(row=0, col=0)
    plot.showGrid(x=True, y=True, alpha=0.2)
    plot.setLogMode(x=bool(first.log_abscissa), y=False)
    legend = legend_below(layout, plot, 0, colors)
    plot.setTitle(f'{first.tone} at {dof}', color=colors['plot_foreground'],
                  size='9pt')

    if specification is not None and dof in specification.response_dof:
        tone = specification.tone(first.tone)
        frequencies = np.sort(np.concatenate([level.abscissa
                                              for level in levels]))
        target = tone.target(frequencies)[:, specification.response_dof
                                          .index(dof)]
        plot.plot(frequencies, us.from_si(target, dimension),
                  connect='finite', name='specification',
                  pen=pg.mkPen(colors['specification_curve'],
                               width=STOOD_BACK_WIDTH))

    log_x = bool(first.log_abscissa)
    hollow = pg.mkBrush(0, 0, 0, 0)
    for k, (level, setting) in enumerate(zip(levels, settings)):
        color = curve_color(k, colors)
        x = np.asarray(level.abscissa, dtype=float)
        y = us.from_si(np.abs(level.ordinate[channel]), dimension)
        pen = pg.mkPen(color, width=1.5)
        symbol = SYMBOLS[k % len(SYMBOLS)]
        plot.plot(x, y, pen=pen)
        spots = _marker_spots(x, k, len(levels), log_x)
        plot.plot(x[spots], y[spots], pen=None,
                  symbol=symbol, symbolSize=MARKER_SIZE,
                  symbolPen=pg.mkPen(color), symbolBrush=hollow)
        # the legend's sample: the line and the shape together, drawn
        # nowhere but in the legend
        legend.addItem(pg.PlotDataItem(
            [], [], pen=pen, symbol=symbol, symbolSize=MARKER_SIZE,
            symbolPen=pg.mkPen(color), symbolBrush=hollow),
            setting.describe())

    plot.setLabel('bottom', 'frequency [Hz]')
    plot.setLabel('left', axis_label(dimension, us))
    return len(levels)