Plotting series item

QwtPlotSeriesItem

class qwt.plot_series.QwtPlotSeriesItem(title)[source]

Base class for plot items representing a series of samples

setOrientation(orientation)[source]

Set the orientation of the item. Default is Qt.Horizontal.

The orientation() might be used in specific way by a plot item. F.e. a QwtPlotCurve uses it to identify how to display the curve int QwtPlotCurve.Steps or QwtPlotCurve.Sticks style.

See also

:py:meth`orientation()`

orientation()[source]
Returns:

Orientation of the plot item

See also

:py:meth`setOrientation()`

draw(painter, xMap, yMap, canvasRect)[source]

Draw the complete series

Parameters:
drawSeries(painter, xMap, yMap, canvasRect, from_, to)[source]

Draw a subset of the samples

Parameters:

  • painter (QPainter) – Painter

  • xMap (qwt.scale_map.QwtScaleMap) – Maps x-values into pixel coordinates.

  • yMap (qwt.scale_map.QwtScaleMap) – Maps y-values into pixel coordinates.

  • canvasRect (QRectF) – Contents rectangle of the canvas

  • from (int) – Index of the first point to be painted

  • to (int) – Index of the last point to be painted. If to < 0 the curve will be painted to its last point.

See also

This method is implemented in qwt.plot_curve.QwtPlotCurve

boundingRect()[source]
Returns:

An invalid bounding rect: QRectF(1.0, 1.0, -2.0, -2.0)

Note

A width or height < 0.0 is ignored by the autoscaler

QwtSeriesData

class qwt.plot_series.QwtSeriesData[source]

Abstract interface for iterating over samples

PythonQwt offers several implementations of the QwtSeriesData API, but in situations, where data of an application specific format needs to be displayed, without having to copy it, it is recommended to implement an individual data access.

A subclass of QwtSeriesData must implement:

  • size():

    Should return number of data points.

  • sample()

    Should return values x and y values of the sample at specific position as QPointF object.

  • boundingRect()

    Should return the bounding rectangle of the data series. It is used for autoscaling and might help certain algorithms for displaying the data. The member _boundingRect is intended for caching the calculated rectangle.

setRectOfInterest(rect)[source]

Set a the “rect of interest”

QwtPlotSeriesItem defines the current area of the plot canvas as “rectangle of interest” ( QwtPlotSeriesItem::updateScaleDiv() ). It can be used to implement different levels of details.

The default implementation does nothing.

Parameters:

rect (QRectF) – Rectangle of interest

size()[source]
Returns:

Number of samples

sample(i)[source]

Return a sample

Parameters:

i (int) – Index

Returns:

Sample at position i

boundingRect()[source]

Calculate the bounding rect of all samples

The bounding rect is necessary for autoscaling and can be used for a couple of painting optimizations.

Returns:

Bounding rectangle

QwtPointArrayData

class qwt.plot_series.QwtPointArrayData(x=None, y=None, size=None, finite=None)[source]

Interface for iterating over two array objects

class QwtCQwtPointArrayDataolorMap(x, y[, size=None])
Parameters:

  • x (list or tuple or numpy.array) – Array of x values

  • y (list or tuple or numpy.array) – Array of y values

  • size (int) – Size of the x and y arrays

  • finite (bool) – if True, keep only finite array elements (remove all infinity and not a number values), otherwise do not filter array elements

boundingRect()[source]

Calculate the bounding rectangle

The bounding rectangle is calculated once by iterating over all points and is stored for all following requests.

Returns:

Bounding rectangle

size()[source]
Returns:

Size of the data set

sample(index)[source]
Parameters:

index (int) – Index

Returns:

Sample at position index

xData()[source]
Returns:

Array of the x-values

yData()[source]
Returns:

Array of the y-values

QwtSeriesStore

class qwt.plot_series.QwtSeriesStore[source]

Class storing a QwtSeriesData object

QwtSeriesStore and QwtPlotSeriesItem are intended as base classes for all plot items iterating over a series of samples.

setData(series)[source]

Assign a series of samples

Parameters:

series (qwt.plot_series.QwtSeriesData) – Data

Warning

The item takes ownership of the data object, deleting it when its not used anymore.

data()[source]
Returns:

the series data

sample(index)[source]
Parameters:

index (int) – Index

Returns:

Sample at position index

dataSize()[source]
Returns:

Number of samples of the series

See also

setData(), qwt.plot_series.QwtSeriesData.size()

dataRect()[source]
Returns:

Bounding rectangle of the series or an invalid rectangle, when no series is stored

See also

qwt.plot_series.QwtSeriesData.boundingRect()

setRectOfInterest(rect)[source]

Set a the “rect of interest” for the series

Parameters:

rect (QRectF) – Rectangle of interest

See also

qwt.plot_series.QwtSeriesData.setRectOfInterest()

swapData(series)[source]

Replace a series without deleting the previous one

Parameters:

series (qwt.plot_series.QwtSeriesData) – New series

Returns:

Previously assigned series