PlotDataItem — pyqtgraph 0.9.8 documentation

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# PlotDataItem

class `pyqtgraph.` `PlotDataItem`(*args, **kargs)

  Bases: `GraphicsObject`

  GraphicsItem for displaying plot curves, scatter plots, or both. While it is possible to use `PlotCurveItem` or `ScatterPlotItem` individually, this class provides a unified interface to both. Inspances of `PlotDataItem` are usually created by plot() methods such as `pyqtgraph.plot()` and `PlotItem.plot()`.

  Signals: |
  sigPlotChanged(self) | Emitted when the data in this item is updated.
  sigClicked(self) | Emitted when the item is clicked.
  sigPointsClicked(self, points) | Emitted when a plot point is clicked Sends the list of points under the mouse.

  `__init__`(*args, **kargs)

    There are many different ways to create a PlotDataItem:

    Data initialization arguments: (x,y data only)

    > PlotDataItem(xValues, yValues) | x and y values may be any sequence (including ndarray) of real numbers
    > PlotDataItem(yValues) | y values only – x will be automatically set to range(len(y))
    > PlotDataItem(x=xValues, y=yValues) | x and y given by keyword arguments
    > PlotDataItem(ndarray(Nx2)) | numpy array with shape (N, 2) where x=data[:,0] and y=data[:,1]

    Data initialization arguments: (x,y data AND may include spot style)

    > PlotDataItem(recarray) | numpy array with dtype=[(‘x’, float), (‘y’, float), ...]
    > PlotDataItem(list-of-dicts) | [{‘x’: x, ‘y’: y, ...}, ...]
    > PlotDataItem(dict-of-lists) | {‘x’: [...], ‘y’: [...], ...}
    > PlotDataItem(MetaArray) | 1D array of Y values with X sepecified as axis values OR 2D array with a column ‘y’ and extra columns as needed.

    Line style keyword arguments:

    Point style keyword arguments: (see `ScatterPlotItem.setData()` for more information)

    > symbol | Symbol to use for drawing points OR list of symbols, one per point. Default is no symbol. Options are o, s, t, d, +, or any QPainterPath
    > symbolPen | Outline pen for drawing points OR list of pens, one per point. May be any single argument accepted by `mkPen()`
    > symbolBrush | Brush for filling points OR list of brushes, one per point. May be any single argument accepted by `mkBrush()`
    > symbolSize | Diameter of symbols OR list of diameters.
    > pxMode | (bool) If True, then symbolSize is specified in pixels. If False, then symbolSize is specified in data coordinates.

    Optimization keyword arguments:

    > antialias | (bool) By default, antialiasing is disabled to improve performance. Note that in some cases (in particluar, when pxMode=True), points will be rendered antialiased even if this is set to False.
    > decimate | deprecated.
    > downsample | (int) Reduce the number of samples displayed by this value
    > downsampleMethod | ‘subsample’: Downsample by taking the first of N samples. This method is fastest and least accurate. ‘mean’: Downsample by taking the mean of N samples. ‘peak’: Downsample by drawing a saw wave that follows the min and max of the original data. This method produces the best visual representation of the data but is slower.
    > autoDownsample | (bool) If True, resample the data before plotting to avoid plotting multiple line segments per pixel. This can improve performance when viewing very high-density data, but increases the initial overhead and memory usage.
    > clipToView | (bool) If True, only plot data that is visible within the X range of the containing ViewBox. This can improve performance when plotting very large data sets where only a fraction of the data is visible at any time.
    > identical | deprecated

    Meta-info keyword arguments:

    > name | name of dataset. This would appear in a legend

  `dataBounds`(ax, frac=1.0, orthoRange=None)

    Returns the range occupied by the data (along a specific axis) in this item. This method is called by ViewBox when auto-scaling.

    Arguments: |
    ax | (0 or 1) the axis for which to return this item’s data range
    frac | (float 0.0-1.0) Specifies what fraction of the total data range to return. By default, the entire range is returned. This allows the ViewBox to ignore large spikes in the data when auto-scaling.
    orthoRange | ([min,max] or None) Specifies that only the data within the given range (orthogonal to ax) should me measured when returning the data range. (For example, a ViewBox might ask what is the y-range of all data with x-values between min and max)

  `pixelPadding`()

    Return the size in pixels that this item may draw beyond the values returned by dataBounds(). This method is called by ViewBox when auto-scaling.

  `setData`(*args, **kargs)

    Clear any data displayed by this item and display new data. See `__init__()` for details; it accepts the same arguments.

  `setDownsampling`(ds=None, auto=None, method=None)

    Set the downsampling mode of this item. Downsampling reduces the number of samples drawn to increase performance.

    Arguments |
    ds | (int) Reduce visible plot samples by this factor. To disable, set ds=1.
    auto | (bool) If True, automatically pick ds based on visible range
    mode | ‘subsample’: Downsample by taking the first of N samples. This method is fastest and least accurate. ‘mean’: Downsample by taking the mean of N samples. ‘peak’: Downsample by drawing a saw wave that follows the min and max of the original data. This method produces the best visual representation of the data but is slower.

  `setPen`(*args, **kargs)
    Sets the pen used to draw lines between points.
    pen can be a QPen or any argument accepted by `pyqtgraph.mkPen()`
  `setShadowPen`(*args, **kargs)
    Sets the shadow pen used to draw lines between points (this is for enhancing contrast or emphacizing data).
    This line is drawn behind the primary pen (see `setPen()`) and should generally be assigned greater width than the primary pen.
    pen can be a QPen or any argument accepted by `pyqtgraph.mkPen()`

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