PlotItem#

class pyqtgraph.PlotItem(
parent: QObject | None = None,
name: str | None = None,
labels: dict[str, str] | None = None,
title: str | None = None,
viewBox: ViewBox | None = None,
axisItems: dict[str, AxisItem] | None = None,
enableMenu: bool = True,
**kwargs,
)[source]#

GraphicsWidget implementing a standard 2D plotting area with axes.

Bases: GraphicsWidget

This class provides the ViewBox-plus-axes that appear when using pg.plot(), PlotWidget, and :meth :GraphicsLayout.addPlot() <pyqtgraph.GraphicsLayout.addPlot>.

It’s main functionality is:

  • Manage placement of ViewBox, AxisItems, and LabelItems

  • Create and manage a list of PlotDataItems displayed inside the ViewBox

  • Implement a context menu with commonly used display and analysis options

Use plot() to create a new PlotDataItem and add it to the view. Use addItem() to add any QGraphicsItem to the view.

This class wraps several methods from its internal ViewBox:

The ViewBox itself can be accessed by calling getViewBox()

Parameters:

  • parent (QObject or None, default None) – Parent QObject assign to the PlotItem.

  • name (str or None, default None) – Register the value for this view so that others may link to it.

  • labels (dict of str or None, default None) – A dictionary specifying the axis labels to display

    {'left': (args), 'bottom': (args), ...}

    The name of each axis and the corresponding arguments are passed to PlotItem.setLabel() Optionally, PlotItem my also be initialized with the keyword arguments left, right, top, or bottom to achieve the same effect.

  • title (str) – Text to set the title of the PlotItem to.

  • viewBox (ViewBox or None, default None) – Have the PlotItem use the provided ViewBox. If not specified, the PlotItem will be constructed with this as its ViewBox.

  • axisItems (dict of {'left', 'bottom', 'right', 'top } and AxisItem or None) – Pass pre-constructed AxisItem objects to be used for the left, bottom, right or top axis. Default is None.

  • enableMenu (bool) – Toggle the enabling or disabling of the right-click context menu.

  • **kwargs (dict, optional) – Any extra keyword arguments are passed to PlotItem.plot().

Signals:

  • sigYRangeChanged (Signal) – Signal is emitted when the range on the y-axis changes. Signal contains a reference to the ViewBox, and tuple of (xmin, xmax).

  • sigXRangeChanged (Signal) – Signal is emitted when the range on the x-axis changes. Signal contains a reference to the ViewBox, and tuple of (ymin, ymax).

  • sigRangeChanged (Signal) – Signal is emitted when the range on either x or y-axis changes. Signal contains a reference to the ViewBox, a list of lists of the form, [[x_min, x_max], [y_min, y_max]] and a list of two booleans, indicating if the range on which axis has changed of the form [x_range_changed, y_range_changed].

__init__(
parent: QObject | None = None,
name: str | None = None,
labels: dict[str, str] | None = None,
title: str | None = None,
viewBox: ViewBox | None = None,
axisItems: dict[str, AxisItem] | None = None,
enableMenu: bool = True,
**kwargs,
)[source]#
addColorBar(
image,
**kwargs,
)[source]#

Add a ColorBarItem and set to the provided image.

A call like plot.addColorBar(img, colorMap='viridis') is a convenient method to assign and show a color map.

Parameters:
Returns:

The newly created ColorBarItem instance.

Return type:

ColorBarItem

addItem(
item,
*args,
**kwargs,
)[source]#

Add a GraphicsItem to the ViewBox.

If the item has plot data (PlotDataItem , PlotCurveItem, ScatterPlotItem ), it may be included in analysis performed by the PlotItem.

Parameters:

  • item (GraphicsItem) – Item to add to the ViewBox.

  • *args (tuple) – Arguments relayed to addItem().

  • **kwargs (dict) – Keyword arguments for adding an item. Supported arguments include.

    Property

    Description

    ignoreBounds

    bool - Keyword argument relayed to addItem().

    skipAverage

    bool - If True, do not use curve to compute average curves.

See also

addItem()

See method for supported arguments to be passed.

addLegend(
offset=(30, 30),
**kwargs,
)[source]#

Add a new LegendItem.

After the LegendItem is created, it is anchored in the internal ViewBox. Plots added after this will be automatically displayed in the legend if they are created with a ‘name’ argument.

If a LegendItem has already been created using this method, that item will be returned rather than creating a new one.

Parameters:

  • offset (tuple of int, int) – The distance to offset the LegendItem, defaults to (30, 30).

  • **kwargs (dict, optional) – Keyword argument passed to the LegendItem constructor.

Returns:

The instance of LegendItem that was constructed.

Return type:

LegendItem

addLine(
x=None,
y=None,
z=None,
**kwargs,
)[source]#

Create a new InfiniteLine and add it to the plot.

Parameters:

  • x (float or None) – Position in the x-axis to draw the line. If specified, the line will be vertical. Default None.

  • y (float or None) – Position in the y-axis to draw the line. If specified, the line will be horizontal. Default None.

  • z (int or None) – Z value to set the line to. This is used to determine which items are on top of the other. See setZValue().

  • **kwargs (dict) – Keyword arguments to pass to the InfiniteLine instance.

Returns:

The new InfiniteLine added.

Return type:

InfiniteLine

clear()[source]#

Remove all items from the PlotItem’s ViewBox.

clearPlots()[source]#

Remove all curves from the PlotItem’s ViewBox.

clipToViewMode() → bool[source]#

Return whether clip-to-view mode is enabled.

Returns:

True if clip-to-view mode is enabled, False otherwise.

Return type:

bool

getAxis(
name,
)[source]#

Return the specified AxisItem.

Parameters:

name ({'left', 'bottom', 'right', 'top'}) – The name of the axis to return.

Returns:

The AxisItem.

Return type:

AxisItem

Raises:

KeyError – If the specified axis is not present.

getViewBox() → ViewBox[source]#

Return the embedded ViewBox.

Returns:

The ViewBox that this PlotItem uses.

Return type:

ViewBox

hideAxis(
axis,
)[source]#

Hide an axis.

Parameters:

axis ({'left', 'bottom', 'right', 'top'}) – The axis to hide.

hideButtons()[source]#

Hide auto-scale button (‘A’ in lower-left corner).

listDataItems()[source]#

Return a list of all data items current plotted.

Returns:

A copy of a list of the data items.

Return type:

list of PlotCurveItem, ScatterPlotItem or PlotDataItem

menuEnabled()[source]#

Return whether the context menu is enabled.

Returns:

True if the context menu is enabled, False otherwise.

Return type:

bool

multiDataPlot(
*,
x=None,
y=None,
constKwargs=None,
**kwargs,
)[source]#

Allow plotting multiple curves on the same plot in one call.

Parameters:

  • x, y (array_like) –

    Can be in the following formats:

    • {x or y} = [n1, n2, n3, …]: The named argument iterates through n curves, while the unspecified argument is range(len(n)) for each curve.

    • x, [y1, y2, y3, …]

    • [x1, x2, x3, …], [y1, y2, y3, …]

    • [x1, x2, x3, …], y

    where x_n and y_n are ndarray data for each curve. Since x and y values are matched using zip, unequal lengths mean the longer array will be truncated. Note that 2D matrices for either x or y are considered lists of curve data.

  • constKwargs (dict, optional) – A dict of {str: value} passed to each curve during plot().

  • **kwargs (dict, optional) – A dict of {str: iterable} where the str is the name of a kwarg and the iterable is a list of values, one for each plotted curve.

Returns:

Returns a list of the newly constructed PlotDataItem instances representing the new curves.

Return type:

list of PlotDataItem

plot(
*args,
**kwargs,
)[source]#

Add and return a new PlotDataItem.

Parameters:

  • *args (tuple, optional) – Arguments that are passed to the PlotDataItem constructor.

  • **kwargs (dict, optional) – Keyword arguments that are passed to the PlotDataItem constructor. In addition, the following keyword arguments are accepted.

    Property

    Description

    clear

    bool - Call clear() prior to creating the new plot instance.

    params

    dict or None - Arguments to passed as the params argument to addItem().
Returns:

The newly created PlotDataItem.

Return type:

PlotDataItem

removeItem(
item,
)[source]#

Remove an item from the plot.

Parameters:

item (GraphicsItem) – The item to remove.

scatterPlot(
*args,
**kwargs,
)[source]#

Create a PlotDataItem and add it to the plot.

The PlotDataItem instance will render the underlying data in a scatter plot form.

Parameters:

  • *args (tuple, optional) – Arguments that are passed to the PlotDataItem constructor.

  • **kwargs (dict, optional) – Keyword arguments that are passed to the PlotDataItem constructor. In addition, the following keyword arguments are accepted.

    Property

    Description

    pen

    QPen - Sets the pen used to draw lines or symbols for the plot. Equivalent to symbolPen.

    brush

    QBrush - Sets the brush used to fill symbols for the plot. Equivalent to symbolBrush.

    size

    float - Sets the symbol size for the plot. Equivalent to symbolSize.
Returns:

The newly created PlotDataItem.

Return type:

PlotDataItem

setAxisItems(
axisItems: dict[str, AxisItem] | None = None,
) → None[source]#

Place axis items and initializes non-existing axis items.

Parameters:

axisItems (dict of str and AxisItem or None) – Optional dictionary instructing the PlotItem to use pre-constructed items for its axes. The dict keys must be axis names {‘left’, ‘bottom’, ‘right’, ‘top’} and the values must be instances of AxisItem.

Return type:

None

setClipToView(
clip,
)[source]#

Set the default clip-to-view mode for new curves.

Parameters:

clip (bool) – If True, new curves will be clipped to the view box.

setContextMenuActionVisible(
name: str,
visible: bool,
) → None[source]#

Change the context menu action visibility.

Parameters:

  • name ({'Transforms', 'Downsample', 'Average', 'Alpha', 'Grid', 'Points'}) – Action name.

  • visible (bool) – Determines if action will be display. True action is visible, False action is invisible.

Return type:

None

setDownsampling(
ds=None,
auto=None,
mode=None,
)[source]#

Set the downsampling mode for the PlotItem.

Downsampling reduces the number of samples drawn to improve performance. The downsampling mode can be set to ‘subsample’, ‘mean’, ‘peak’, or None. If downsampling is enabled, the view will display downsampled data when zoomed out, but will display original data at high zoom levels.

Parameters:

  • ds (int or bool or None, optional) – The downsampling factor. If None, the downsampling factor is not changed. If True, the downsampling factor is set to the value in the downsampling spin box. If False, downsampling is disabled. If an integer, the downsampling factor is set to this value. Default is None.

  • auto (bool or None, optional) – If True, automatic downsampling is enabled. If False, automatic downsampling is disabled. If None, the automatic downsampling setting is not changed. Default is None.

  • mode ({'subsample', 'mean', 'peak'} or None, optional) – The downsampling mode. If None, the downsampling mode is not changed. Default is None.

Raises:

ValueError – Raised if the specified downsample mode is not recognized.

setExportMode(
export: bool,
opts=None,
)[source]#

Set whether the item will allow export via screenshots or image files.

If export mode is enabled, then the item will allow export and the export options dock will be displayed. If export mode is disabled, then no export options will be available and the export dock will be hidden.

Parameters:

  • export (bool) – If True, the item will allow export.

  • opts (dict or None, optional) – A dictionary of export options. If None, the default export options will be used. By default, None.

setLabel(
axis: str,
*args,
**kwargs,
)[source]#

Set the label for an axis.

Basic HTML is allowed. See AxisItem.setLabel() for formatting options.

Parameters:

  • axis ({'left', 'bottom', 'right', 'top'}) – Specify which AxisItem to set the label for.

  • *args (tuple, optional) – All extra arguments are passed to setLabel().

  • **kwargs (dict, optional) – Keyword arguments are passed to setLabel().

setLabels(
**kwargs,
)[source]#

Set the axis labels of the plot.

Parameters:

**kwargs (dict, optional) – Keyword arguments are passed to setLabel(). The special keyword title can be used to set the plot title using setTitle().

setLogMode(
x=None,
y=None,
)[source]#

Set log scaling for x and/or y axes.

This informs PlotDataItems to transform logarithmically and switches the axes to use log ticking.

Parameters:

  • x (bool or None) – If True, set the x-axis to log mode. A value of None is ignored.

  • y (bool or None) – If True, set the y-axis to log mode. A value of None is ignored.

Notes

No other items, in the scene will be affected by this; there is (currently) no generic way to redisplay a GraphicsItem with log coordinates.

setMenuEnabled(
enableMenu=True,
enableViewBoxMenu='same',
)[source]#

Enable or disable the context menu for this PlotItem.

By default, the ViewBox’s context menu will also be affected. Use enableViewBoxMenu=None to leave the ViewBox unchanged.

Parameters:

  • enableMenu (bool, optional) – Whether to enable or disable the context menu, by default True.

  • enableViewBoxMenu (str or bool, optional) – Whether to enable or disable the ViewBox context menu. If ‘same’, the ViewBox menu will be enabled or disabled as enableMenu. If True or False, the ViewBox menu will be set accordingly. If None, the ViewBox menu will not be changed. By default ‘same’.

setTitle(
title=None,
**args,
)[source]#

Set the title of the plot.

Parameters:

  • title (str, optional) – The title text. If None, the title will be hidden. The default is None.

  • **args (dict) – Additional keyword arguments are passed to setText().

showAxes(
selection,
showValues=True,
size=False,
)[source]#

Convenience method for quickly configuring axis settings.

Parameters:

  • selection (bool or tuple of bool) – Determines which AxisItems will be displayed. If in tuple form, order is (left, top, right, bottom). A single boolean value will set all axes, so that showAxes(True) configures the axes to draw a frame.

  • showValues (bool or tuple of bool, optional) – Determines if values will be displayed for the ticks of each axis. True value shows values for left and bottom axis (default). False shows no values. If in tuple form, order is (left, top, right, bottom). None leaves settings unchanged. If not specified, left and bottom axes will be drawn with values.

  • size (float or tuple of float, optional) – Reserves as fixed amount of space (width for vertical axis, height for horizontal axis) for each axis where tick values are enabled. If only a single float value is given, it will be applied for both width and height. If None is given instead of a float value, the axis reverts to automatic allocation of space. If in tuple form, order is (width, height).

showAxis(
axis: str,
show: bool = True,
)[source]#

Show or hide an axis.

Parameters:

  • axis ({'left', 'bottom', 'right', 'top'}) – The axis to show or hide.

  • show (bool, optional) – Whether to show or hide the axis, by default True.

showButtons()[source]#

Show auto-scale button (‘A’ in lower-left corner).

showGrid(
x=None,
y=None,
alpha=None,
)[source]#

Show or hide the grid for either axis.

Parameters:

  • x (bool or None) – Show the X grid, a value of None is ignored.

  • y (bool or None) – Show the Y grid, a value of None is ignored.

  • alpha (float or None) – Opacity of the grid, float values need to be between [0.0, 1.0].

showLabel(
axis,
show=True,
)[source]#

Show or hide one of the plot’s axis labels.

Parameters:

  • axis ({'left', 'bottom', 'right', 'top'}) – The axis label to show or hide.

  • show (bool, optional) – Whether to show or hide the label, by default True.

viewGeometry() → QRectF[source]#

Return the screen geometry of the viewbox.

Returns:

The QRectF instance that contains the view area.

Return type:

QRectF

writeCsv(
fileName=None,
)[source]#

Write the plot data to a CSV file.

Parameters:

fileName (str, optional) – The name of the file to write to. If not specified, a file dialog will be opened.

writeImage(
fileName=None,
)[source]#

Write the plot content to an image file.

Parameters:

fileName (str, optional) – The name of the file to write to. If not specified, a file dialog will be opened.

writeSvg(
fileName=None,
)[source]#

Write the plot content to an SVG file.

Parameters:

fileName (str, optional) – The name of the file to write to. If not specified, a file dialog will be opened.