matplotlib.backend_bases#

Abstract base classes define the primitives that renderers and graphics contexts must implement to serve as a Matplotlib backend.

RendererBase

An abstract base class to handle drawing/rendering operations.

FigureCanvasBase

The abstraction layer that separates the Figure from the backend specific details like a user interface drawing area.

GraphicsContextBase

An abstract base class that provides color, line styles, etc.

Event

The base class for all of the Matplotlib event handling. Derived classes such as KeyEvent and MouseEvent store the meta data like keys and buttons pressed, x and y locations in pixel and Axes coordinates.

ShowBase

The base class for the Show class of each interactive backend; the 'show' callable is then set to Show.__call__.

ToolContainerBase

The base class for the Toolbar class of each interactive backend.

class matplotlib.backend_bases.CloseEvent(name, canvas, guiEvent=None)[source]#

Bases: Event

An event triggered by a figure being closed.

class matplotlib.backend_bases.DrawEvent(name, canvas, renderer)[source]#

Bases: Event

An event triggered by a draw operation on the canvas.

In most backends, callbacks subscribed to this event will be fired after the rendering is complete but before the screen is updated. Any extra artists drawn to the canvas's renderer will be reflected without an explicit call to blit.

Warning

Calling canvas.draw and canvas.blit in these callbacks may not be safe with all backends and may cause infinite recursion.

A DrawEvent has a number of special attributes in addition to those defined by the parent Event class.

Attributes:

rendererRendererBase

The renderer for the draw event.

class matplotlib.backend_bases.Event(name, canvas, guiEvent=None)[source]#

Bases: object

A Matplotlib event.

The following attributes are defined and shown with their default values. Subclasses may define additional attributes.

Attributes:

namestr

The event name.

canvasFigureCanvasBase

The backend-specific canvas instance generating the event.

guiEvent

The GUI event that triggered the Matplotlib event.

class matplotlib.backend_bases.FigureCanvasBase(figure=None)[source]#

Bases: object

The canvas the figure renders into.

Attributes:

figureFigure

A high-level figure instance.

blit(bbox=None)[source]#

Blit the canvas in bbox (default entire canvas).

property button_pick_id#

property callbacks#

property device_pixel_ratio#

The ratio of physical to logical pixels used for the canvas on screen.

By default, this is 1, meaning physical and logical pixels are the same size. Subclasses that support High DPI screens may set this property to indicate that said ratio is different. All Matplotlib interaction, unless working directly with the canvas, remains in logical pixels.

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

Render the Figure.

This method must walk the artist tree, even if no output is produced, because it triggers deferred work that users may want to access before saving output to disk. For example computing limits, auto-limits, and tick values.

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

Request a widget redraw once control returns to the GUI event loop.

Even if multiple calls to draw_idle occur before control returns to the GUI event loop, the figure will only be rendered once.

Notes

Backends may choose to override the method and implement their own strategy to prevent multiple renderings.

events = ['resize_event', 'draw_event', 'key_press_event', 'key_release_event', 'button_press_event', 'button_release_event', 'scroll_event', 'motion_notify_event', 'pick_event', 'figure_enter_event', 'figure_leave_event', 'axes_enter_event', 'axes_leave_event', 'close_event']#

filetypes = {'avif': 'AV1 Image File Format', 'eps': 'Encapsulated Postscript', 'gif': 'Graphics Interchange Format', 'jpeg': 'Joint Photographic Experts Group', 'jpg': 'Joint Photographic Experts Group', 'pdf': 'Portable Document Format', 'pgf': 'PGF code for LaTeX', 'png': 'Portable Network Graphics', 'ps': 'Postscript', 'raw': 'Raw RGBA bitmap', 'rgba': 'Raw RGBA bitmap', 'svg': 'Scalable Vector Graphics', 'svgz': 'Scalable Vector Graphics', 'tif': 'Tagged Image File Format', 'tiff': 'Tagged Image File Format', 'webp': 'WebP Image Format'}#

fixed_dpi = None#

flush_events()[source]#

Flush the GUI events for the figure.

Interactive backends need to reimplement this method.

get_default_filename()[source]#

Return a suitable default filename, including the extension.

classmethod get_default_filetype()[source]#

Return the default savefig file format as specified in rcParams["savefig.format"] (default: 'png').

The returned string does not include a period. This method is overridden in backends that only support a single file type.

classmethod get_supported_filetypes()[source]#

Return dict of savefig file formats supported by this backend.

classmethod get_supported_filetypes_grouped()[source]#

Return a dict of savefig file formats supported by this backend, where the keys are a file type name, such as 'Joint Photographic Experts Group', and the values are a list of filename extensions used for that filetype, such as ['jpg', 'jpeg'].

get_width_height(*, physical=False)[source]#

Return the figure width and height in integral points or pixels.

When the figure is used on High DPI screens (and the backend supports it), the truncation to integers occurs after scaling by the device pixel ratio.

Parameters:

physicalbool, default: False

Whether to return true physical pixels or logical pixels. Physical pixels may be used by backends that support HiDPI, but still configure the canvas using its actual size.

Returns:

width, heightint

The size of the figure, in points or pixels, depending on the backend.

Notes

This method normally truncates the height/width to remove any fractional pixel. However, if the height/width is extremely close to the integer pixel (within 1e-8 pixel), the height/width is instead rounded up to account for floating-point precision effects.

grab_mouse(ax)[source]#

Set the child Axes which is grabbing the mouse events.

Usually called by the widgets themselves. It is an error to call this if the mouse is already grabbed by another Axes.

inaxes(xy)[source]#

Return the topmost visible Axes containing the point xy.

Parameters:

xy(float, float)

(x, y) pixel positions from left/bottom of the canvas.

Returns:

Axes or None

The topmost visible Axes containing the point, or None if there is no Axes at the point.

is_saving()[source]#

Return whether the renderer is in the process of saving to a file, rather than rendering for an on-screen buffer.

manager_class[source]#

alias of FigureManagerBase

mpl_connect(s, func)[source]#

Bind function func to event s.

Parameters:

sstr

One of the following events ids:

• 'button_press_event'

• 'button_release_event'

• 'draw_event'

• 'key_press_event'

• 'key_release_event'

• 'motion_notify_event'

• 'pick_event'

• 'resize_event'

• 'scroll_event'

• 'figure_enter_event',

• 'figure_leave_event',

• 'axes_enter_event',

• 'axes_leave_event'

• 'close_event'.

funccallable

The callback function to be executed, which must have the signature:

def func(event: Event) -> Any

For the location events (button and key press/release), if the mouse is over the Axes, the inaxes attribute of the event will be set to the Axes the event occurs is over, and additionally, the variables xdata and ydata attributes will be set to the mouse location in data coordinates. See KeyEvent and MouseEvent for more info.

Note

If func is a method, this only stores a weak reference to the method. Thus, the figure does not influence the lifetime of the associated object. Usually, you want to make sure that the object is kept alive throughout the lifetime of the figure by holding a reference to it.

Returns:

cid

A connection id that can be used with FigureCanvasBase.mpl_disconnect.

Examples

def on_press(event):
    print('you pressed', event.button, event.xdata, event.ydata)

cid = canvas.mpl_connect('button_press_event', on_press)

mpl_disconnect(cid)[source]#

Disconnect the callback with id cid.

Examples

cid = canvas.mpl_connect('button_press_event', on_press)
# ... later
canvas.mpl_disconnect(cid)

classmethod new_manager(figure, num)[source]#

Create a new figure manager for figure, using this canvas class.

Notes

This method should not be reimplemented in subclasses. If custom manager creation logic is needed, please reimplement FigureManager.create_with_canvas.

new_timer(interval=None, callbacks=None)[source]#

Create a new backend-specific subclass of TimerBase.

This is useful for getting periodic events through the backend's native event loop. Implemented only for backends with GUIs.

Parameters:

intervalint

Timer interval in milliseconds.

callbackslist[tuple[callable, tuple, dict]]

Sequence of (func, args, kwargs) where func(*args, **kwargs) will be executed by the timer every interval.

Callbacks which return False or 0 will be removed from the timer.

Examples

>>> timer = fig.canvas.new_timer(callbacks=[(f1, (1,), {'a': 3})])

print_figure(filename, dpi=None, facecolor=None, edgecolor=None, orientation='portrait', format=None, *, bbox_inches=None, pad_inches=None, bbox_extra_artists=None, backend=None, **kwargs)[source]#

Render the figure to hardcopy. Set the figure patch face and edge colors. This is useful because some of the GUIs have a gray figure face color background and you'll probably want to override this on hardcopy.

Parameters:

filenamestr or path-like or file-like

The file where the figure is saved.

dpifloat, default: rcParams["savefig.dpi"] (default: 'figure')

The dots per inch to save the figure in.

facecolorcolor or 'auto', default: rcParams["savefig.facecolor"] (default: 'auto')

The facecolor of the figure. If 'auto', use the current figure facecolor.

edgecolorcolor or 'auto', default: rcParams["savefig.edgecolor"] (default: 'auto')

The edgecolor of the figure. If 'auto', use the current figure edgecolor.

orientation{'landscape', 'portrait'}, default: 'portrait'

Only currently applies to PostScript printing.

formatstr, optional

Force a specific file format. If not given, the format is inferred from the filename extension, and if that fails from rcParams["savefig.format"] (default: 'png').

bbox_inches'tight' or Bbox, default: rcParams["savefig.bbox"] (default: None)

Bounding box in inches: only the given portion of the figure is saved. If 'tight', try to figure out the tight bbox of the figure.

pad_inchesfloat or 'layout', default: rcParams["savefig.pad_inches"] (default: 0.1)

Amount of padding in inches around the figure when bbox_inches is 'tight'. If 'layout' use the padding from the constrained or compressed layout engine; ignored if one of those engines is not in use.

bbox_extra_artistslist of Artist, optional

A list of extra artists that will be considered when the tight bbox is calculated.

backendstr, optional

Use a non-default backend to render the file, e.g. to render a png file with the "cairo" backend rather than the default "agg", or a pdf file with the "pgf" backend rather than the default "pdf". Note that the default backend is normally sufficient. See The builtin backends for a list of valid backends for each file format. Custom backends can be referenced as "module://...".

release_mouse(ax)[source]#

Release the mouse grab held by the Axes ax.

Usually called by the widgets. It is ok to call this even if ax doesn't have the mouse grab currently.

required_interactive_framework = None#

property scroll_pick_id#

set_cursor(cursor)[source]#

Set the current cursor.

This may have no effect if the backend does not display anything.

If required by the backend, this method should trigger an update in the backend event loop after the cursor is set, as this method may be called e.g. before a long-running task during which the GUI is not updated.

Parameters:

cursorCursors

The cursor to display over the canvas. Note: some backends may change the cursor for the entire window.

start_event_loop(timeout=0)[source]#

Start a blocking event loop.

Such an event loop is used by interactive functions, such as ginput and waitforbuttonpress, to wait for events.

The event loop blocks until a callback function triggers stop_event_loop, or timeout is reached.

If timeout is 0 or negative, never timeout.

Only interactive backends need to reimplement this method and it relies on flush_events being properly implemented.

Interactive backends should implement this in a more native way.

stop_event_loop()[source]#

Stop the current blocking event loop.

Interactive backends need to reimplement this to match start_event_loop

supports_blit = False#

class matplotlib.backend_bases.FigureManagerBase(canvas, num)[source]#

Bases: object

A backend-independent abstraction of a figure container and controller.

The figure manager is used by pyplot to interact with the window in a backend-independent way. It's an adapter for the real (GUI) framework that represents the visual figure on screen.

The figure manager is connected to a specific canvas instance, which in turn is connected to a specific figure instance. To access a figure manager for a given figure in user code, you typically use fig.canvas.manager.

GUI backends derive from this class to translate common operations such as show or resize to the GUI-specific code. Non-GUI backends do not support these operations and can just use the base class.

This following basic operations are accessible:

Window operations

• show

• destroy

• full_screen_toggle

• resize

• get_window_title

• set_window_title

Key and mouse button press handling

The figure manager sets up default key and mouse button press handling by hooking up the key_press_handler to the matplotlib event system. This ensures the same shortcuts and mouse actions across backends.

Other operations

Subclasses will have additional attributes and functions to access additional functionality. This is of course backend-specific. For example, most GUI backends have window and toolbar attributes that give access to the native GUI widgets of the respective framework.

Attributes:

canvasFigureCanvasBase

The backend-specific canvas instance.

numint or str

The figure number.

key_press_handler_idint

The default key handler cid, when using the toolmanager. To disable the default key press handling use:

figure.canvas.mpl_disconnect(
    figure.canvas.manager.key_press_handler_id)

button_press_handler_idint

The default mouse button handler cid, when using the toolmanager. To disable the default button press handling use:

figure.canvas.mpl_disconnect(
    figure.canvas.manager.button_press_handler_id)

classmethod create_with_canvas(canvas_class, figure, num)[source]#

Create a manager for a given figure using a specific canvas_class.

Backends should override this method if they have specific needs for setting up the canvas or the manager.

destroy()[source]#

full_screen_toggle()[source]#

get_window_title()[source]#

Return the title text of the window containing the figure.

classmethod pyplot_show(*, block=None)[source]#

Show all figures. This method is the implementation of pyplot.show.

To customize the behavior of pyplot.show, interactive backends should usually override start_main_loop; if more customized logic is necessary, pyplot_show can also be overridden.

Parameters:

blockbool, optional

Whether to block by calling start_main_loop. The default, None, means to block if we are neither in IPython's %pylab mode nor in interactive mode.

resize(w, h)[source]#

For GUI backends, resize the window (in physical pixels).

set_window_title(title)[source]#

Set the title text of the window containing the figure.

Examples

>>> fig = plt.figure()
>>> fig.canvas.manager.set_window_title('My figure')

show()[source]#

For GUI backends, show the figure window and redraw. For non-GUI backends, raise an exception, unless running headless (i.e. on Linux with an unset DISPLAY); this exception is converted to a warning in Figure.show.

classmethod start_main_loop()[source]#

Start the main event loop.

This method is called by FigureManagerBase.pyplot_show, which is the implementation of pyplot.show. To customize the behavior of pyplot.show, interactive backends should usually override start_main_loop; if more customized logic is necessary, pyplot_show can also be overridden.

class matplotlib.backend_bases.GraphicsContextBase[source]#

Bases: object

An abstract base class that provides color, line styles, etc.

copy_properties(gc)[source]#

Copy properties from gc to self.

get_alpha()[source]#

Return the alpha value used for blending - not supported on all backends.

get_antialiased()[source]#

Return whether the object should try to do antialiased rendering.

get_capstyle()[source]#

Return the CapStyle.

get_clip_path()[source]#

Return the clip path in the form (path, transform), where path is a Path instance, and transform is an affine transform to apply to the path before clipping.

get_clip_rectangle()[source]#

Return the clip rectangle as a Bbox instance.

get_dashes()[source]#

Return the dash style as an (offset, dash-list) pair.

See set_dashes for details.

Default value is (None, None).

get_forced_alpha()[source]#

Return whether the value given by get_alpha() should be used to override any other alpha-channel values.

get_gid()[source]#

Return the object identifier if one is set, None otherwise.

get_hatch()[source]#

Get the current hatch style.

get_hatch_color()[source]#

Get the hatch color.

get_hatch_linewidth()[source]#

Get the hatch linewidth.

get_hatch_path(density=6.0)[source]#

Return a Path for the current hatch.

get_joinstyle()[source]#

Return the JoinStyle.

get_linewidth()[source]#

Return the line width in points.

get_rgb()[source]#

Return a tuple of three or four floats from 0-1.

get_sketch_params()[source]#

Return the sketch parameters for the artist.

Returns:

tuple or None

A 3-tuple with the following elements:

• scale: The amplitude of the wiggle perpendicular to the source line.

• length: The length of the wiggle along the line.

• randomness: The scale factor by which the length is shrunken or expanded.

May return None if no sketch parameters were set.

get_snap()[source]#

Return the snap setting, which can be:

• True: snap vertices to the nearest pixel center

• False: leave vertices as-is

• None: (auto) If the path contains only rectilinear line segments, round to the nearest pixel center

get_url()[source]#

Return a url if one is set, None otherwise.

restore()[source]#

Restore the graphics context from the stack - needed only for backends that save graphics contexts on a stack.

set_alpha(alpha)[source]#

Set the alpha value used for blending - not supported on all backends.

If alpha=None (the default), the alpha components of the foreground and fill colors will be used to set their respective transparencies (where applicable); otherwise, alpha will override them.

set_antialiased(b)[source]#

Set whether object should be drawn with antialiased rendering.

set_capstyle(cs)[source]#

Set how to draw endpoints of lines.

Parameters:

csCapStyle or {'butt', 'projecting', 'round'}

set_clip_path(path)[source]#

Set the clip path to a TransformedPath or None.

set_clip_rectangle(rectangle)[source]#

Set the clip rectangle to a Bbox or None.

set_dashes(dash_offset, dash_list)[source]#

Set the dash style for the gc.

Parameters:

dash_offsetfloat

Distance, in points, into the dash pattern at which to start the pattern. It is usually set to 0.

dash_listarray-like or None

The on-off sequence as points. None specifies a solid line. All values must otherwise be non-negative (\(\ge 0\)).

Notes

See p. 666 of the PostScript Language Reference for more info.

set_foreground(fg, isRGBA=False)[source]#

Set the foreground color.

Parameters:

fgcolor

isRGBAbool

If fg is known to be an (r, g, b, a) tuple, isRGBA can be set to True to improve performance.

set_gid(id)[source]#

Set the id.

set_hatch(hatch)[source]#

Set the hatch style (for fills).

set_hatch_color(hatch_color)[source]#

Set the hatch color.

set_hatch_linewidth(hatch_linewidth)[source]#

Set the hatch linewidth.

set_joinstyle(js)[source]#

Set how to draw connections between line segments.

Parameters:

jsJoinStyle or {'miter', 'round', 'bevel'}

set_linewidth(w)[source]#

Set the linewidth in points.

set_sketch_params(scale=None, length=None, randomness=None)[source]#

Set the sketch parameters.

Parameters:

scalefloat, optional

The amplitude of the wiggle perpendicular to the source line, in pixels. If scale is None, or not provided, no sketch filter will be provided.

lengthfloat, default: 128

The length of the wiggle along the line, in pixels.

randomnessfloat, default: 16

The scale factor by which the length is shrunken or expanded.

set_snap(snap)[source]#

Set the snap setting which may be:

• True: snap vertices to the nearest pixel center

• False: leave vertices as-is

• None: (auto) If the path contains only rectilinear line segments, round to the nearest pixel center

set_url(url)[source]#

Set the url for links in compatible backends.

class matplotlib.backend_bases.KeyEvent(name, canvas, key, x=0, y=0, guiEvent=None)[source]#

Bases: LocationEvent

A key event (key press, key release).

A KeyEvent has a number of special attributes in addition to those defined by the parent Event and LocationEvent classes.

Attributes:

keyNone or str

The key(s) pressed. Could be None, a single case sensitive Unicode character ("g", "G", "#", etc.), a special key ("control", "shift", "f1", "up", etc.) or a combination of the above (e.g., "ctrl+alt+g", "ctrl+alt+G").

Notes

Modifier keys will be prefixed to the pressed key and will be in the order "ctrl", "alt", "super". The exception to this rule is when the pressed key is itself a modifier key, therefore "ctrl+alt" and "alt+control" can both be valid key values.

Examples

def on_key(event):
    print('you pressed', event.key, event.xdata, event.ydata)

cid = fig.canvas.mpl_connect('key_press_event', on_key)

class matplotlib.backend_bases.LocationEvent(name, canvas, x, y, guiEvent=None, *, modifiers=None)[source]#

Bases: Event

An event that has a screen location.

A LocationEvent has a number of special attributes in addition to those defined by the parent Event class.

Attributes:

x, yint or None

Event location in pixels from bottom left of canvas.

inaxesAxes or None

The Axes instance over which the mouse is, if any.

xdata, ydatafloat or None

Data coordinates of the mouse within inaxes, or None if the mouse is not over an Axes.

modifiersfrozenset[str]

The keyboard modifiers currently being pressed (except for KeyEvent).

class matplotlib.backend_bases.MouseButton(*values)[source]#

Bases: IntEnum

BACK = 8[source]#

FORWARD = 9[source]#

LEFT = 1[source]#

MIDDLE = 2[source]#

RIGHT = 3[source]#

class matplotlib.backend_bases.MouseEvent(name, canvas, x, y, button=None, key=None, step=0, dblclick=False, guiEvent=None, *, buttons=None, modifiers=None)[source]#

Bases: LocationEvent

A mouse event ('button_press_event', 'button_release_event', 'scroll_event', 'motion_notify_event').

A MouseEvent has a number of special attributes in addition to those defined by the parent Event and LocationEvent classes.

Attributes:

buttonNone or MouseButton or {'up', 'down'}

The button pressed. 'up' and 'down' are used for scroll events.

Note that LEFT and RIGHT actually refer to the "primary" and "secondary" buttons, i.e. if the user inverts their left and right buttons ("left-handed setting") then the LEFT button will be the one physically on the right.

If this is unset, name is "scroll_event", and step is nonzero, then this will be set to "up" or "down" depending on the sign of step.

buttonsNone or frozenset

For 'motion_notify_event', the mouse buttons currently being pressed (a set of zero or more MouseButtons); for other events, None.

Note

For 'motion_notify_event', this attribute is more accurate than the button (singular) attribute, which is obtained from the last 'button_press_event' or 'button_release_event' that occurred within the canvas (and thus 1. be wrong if the last change in mouse state occurred when the canvas did not have focus, and 2. cannot report when multiple buttons are pressed).

This attribute is not set for 'button_press_event' and 'button_release_event' because GUI toolkits are inconsistent as to whether they report the button state before or after the press/release occurred.

Warning

On macOS, the Tk backends only report a single button even if multiple buttons are pressed.

keyNone or str

The key pressed when the mouse event triggered, e.g. 'shift'. See KeyEvent.

Warning

This key is currently obtained from the last 'key_press_event' or 'key_release_event' that occurred within the canvas. Thus, if the last change of keyboard state occurred while the canvas did not have focus, this attribute will be wrong. On the other hand, the modifiers attribute should always be correct, but it can only report on modifier keys.

stepfloat

The number of scroll steps (positive for 'up', negative for 'down'). This applies only to 'scroll_event' and defaults to 0 otherwise.

dblclickbool

Whether the event is a double-click. This applies only to 'button_press_event' and is False otherwise. In particular, it's not used in 'button_release_event'.

Examples

def on_press(event):
    print('you pressed', event.button, event.xdata, event.ydata)

cid = fig.canvas.mpl_connect('button_press_event', on_press)

class matplotlib.backend_bases.NavigationToolbar2(canvas)[source]#

Bases: object

Base class for the navigation cursor, version 2.

Backends must implement a canvas that handles connections for 'button_press_event' and 'button_release_event'. See FigureCanvasBase.mpl_connect() for more information.

They must also define

save_figure()

Save the current figure.

draw_rubberband() (optional)

Draw the zoom to rect "rubberband" rectangle.

set_message() (optional)

Display message.

set_history_buttons() (optional)

You can change the history back / forward buttons to indicate disabled / enabled state.

and override __init__ to set up the toolbar -- without forgetting to call the base-class init. Typically, __init__ needs to set up toolbar buttons connected to the home, back, forward, pan, zoom, and save_figure methods and using standard icons in the "images" subdirectory of the data path.

That's it, we'll do the rest!

UNKNOWN_SAVED_STATUS = <object object>#

back(*args)[source]#

Move back up the view lim stack.

For convenience of being directly connected as a GUI callback, which often get passed additional parameters, this method accepts arbitrary parameters, but does not use them.

configure_subplots(*args)[source]#

drag_pan(event)[source]#

Callback for dragging in pan/zoom mode.

drag_zoom(event)[source]#

Callback for dragging in zoom mode.

draw_rubberband(event, x0, y0, x1, y1)[source]#

Draw a rectangle rubberband to indicate zoom limits.

Note that it is not guaranteed that x0 <= x1 and y0 <= y1.

forward(*args)[source]#

Move forward in the view lim stack.

For convenience of being directly connected as a GUI callback, which often get passed additional parameters, this method accepts arbitrary parameters, but does not use them.

home(*args)[source]#

Restore the original view.

For convenience of being directly connected as a GUI callback, which often get passed additional parameters, this method accepts arbitrary parameters, but does not use them.

mouse_move(event)[source]#

pan(*args)[source]#

Toggle the pan/zoom tool.

Pan with left button, zoom with right.

press_pan(event)[source]#

Callback for mouse button press in pan/zoom mode.

press_zoom(event)[source]#

Callback for mouse button press in zoom to rect mode.

push_current()[source]#

Push the current view limits and position onto the stack.

release_pan(event)[source]#

Callback for mouse button release in pan/zoom mode.

release_zoom(event)[source]#

Callback for mouse button release in zoom to rect mode.

remove_rubberband()[source]#

Remove the rubberband.

save_figure(*args)[source]#

Save the current figure.

Backend implementations may choose to return the absolute path of the saved file, if any, as a string.

If no file is created then None is returned.

If the backend does not implement this functionality then NavigationToolbar2.UNKNOWN_SAVED_STATUS is returned.

Returns:

str or NavigationToolbar2.UNKNOWN_SAVED_STATUS or None

The filepath of the saved figure. Returns None if figure is not saved. Returns NavigationToolbar2.UNKNOWN_SAVED_STATUS when the backend does not provide the information.

set_history_buttons()[source]#

Enable or disable the back/forward button.

set_message(s)[source]#

Display a message on toolbar or in status bar.

toolitems = (('Home', 'Reset original view', 'home', 'home'), ('Back', 'Back to previous view', 'back', 'back'), ('Forward', 'Forward to next view', 'forward', 'forward'), (None, None, None, None), ('Pan', 'Left button pans, Right button zooms\nx/y fixes axis, CTRL fixes aspect', 'move', 'pan'), ('Zoom', 'Zoom to rectangle\nx/y fixes axis', 'zoom_to_rect', 'zoom'), ('Subplots', 'Configure subplots', 'subplots', 'configure_subplots'), (None, None, None, None), ('Save', 'Save the figure', 'filesave', 'save_figure'))#

update()[source]#

Reset the Axes stack.

zoom(*args)[source]#

exception matplotlib.backend_bases.NonGuiException[source]#

Bases: Exception

Raised when trying show a figure in a non-GUI backend.

class matplotlib.backend_bases.PickEvent(name, canvas, mouseevent, artist, guiEvent=None, **kwargs)[source]#

Bases: Event

A pick event.

This event is fired when the user picks a location on the canvas sufficiently close to an artist that has been made pickable with Artist.set_picker.

A PickEvent has a number of special attributes in addition to those defined by the parent Event class.

Attributes:

mouseeventMouseEvent

The mouse event that generated the pick.

artistArtist

The picked artist. Note that artists are not pickable by default (see Artist.set_picker).

other

Additional attributes may be present depending on the type of the picked object; e.g., a Line2D pick may define different extra attributes than a PatchCollection pick.

Examples

Bind a function on_pick() to pick events, that prints the coordinates of the picked data point:

ax.plot(np.rand(100), 'o', picker=5)  # 5 points tolerance

def on_pick(event):
    line = event.artist
    xdata, ydata = line.get_data()
    ind = event.ind
    print(f'on pick line: {xdata[ind]:.3f}, {ydata[ind]:.3f}')

cid = fig.canvas.mpl_connect('pick_event', on_pick)

class matplotlib.backend_bases.RendererBase[source]#

Bases: object

An abstract base class to handle drawing/rendering operations.

The following methods must be implemented in the backend for full functionality (though just implementing draw_path alone would give a highly capable backend):

• draw_path

• draw_image

• draw_gouraud_triangles

The following methods should be implemented in the backend for optimization reasons:

• draw_text

• draw_markers

• draw_path_collection

• draw_quad_mesh

close_group(s)[source]#

Close a grouping element with label s.

Only used by the SVG renderer.

draw_gouraud_triangles(gc, triangles_array, colors_array, transform)[source]#

Draw a series of Gouraud triangles.

Parameters:

gcGraphicsContextBase

The graphics context.

triangles_array(N, 3, 2) array-like

Array of N (x, y) points for the triangles.

colors_array(N, 3, 4) array-like

Array of N RGBA colors for each point of the triangles.

transformTransform

An affine transform to apply to the points.

draw_image(gc, x, y, im, transform=None)[source]#

Draw an RGBA image.

Parameters:

gcGraphicsContextBase

A graphics context with clipping information.

xfloat

The distance in physical units (i.e., dots or pixels) from the left hand side of the canvas.

yfloat

The distance in physical units (i.e., dots or pixels) from the bottom side of the canvas.

im(N, M, 4) array of numpy.uint8

An array of RGBA pixels.

transformAffine2DBase

If and only if the concrete backend is written such that option_scale_image returns True, an affine transformation (i.e., an Affine2DBase) may be passed to draw_image. The translation vector of the transformation is given in physical units (i.e., dots or pixels). Note that the transformation does not override x and y, and has to be applied before translatingthe result by x and y (this can be accomplished by adding x and y to the translation vector defined by transform).

draw_markers(gc, marker_path, marker_trans, path, trans, rgbFace=None)[source]#

Draw a marker at each of path's vertices (excluding control points).

The base (fallback) implementation makes multiple calls to draw_path. Backends may want to override this method in order to draw the marker only once and reuse it multiple times.

Parameters:

gcGraphicsContextBase

The graphics context.

marker_pathPath

The path for the marker.

marker_transTransform

An affine transform applied to the marker.

pathPath

The locations to draw the markers.

transTransform

An affine transform applied to the path.

rgbFacecolor, optional

draw_path(gc, path, transform, rgbFace=None)[source]#

Draw a Path instance using the given affine transform.

draw_path_collection(gc, master_transform, paths, all_transforms, offsets, offset_trans, facecolors, edgecolors, linewidths, linestyles, antialiaseds, urls, offset_position, *, hatchcolors=None)[source]#

Draw a collection of paths.

Each path is first transformed by the corresponding entry in all_transforms (a list of (3, 3) matrices) and then by master_transform. They are then translated by the corresponding entry in offsets, which has been first transformed by offset_trans.

facecolors, edgecolors, linewidths, linestyles, antialiased and hatchcolors are lists that set the corresponding properties.

Added in version 3.11: Allow hatchcolors to be specified.

offset_position is unused now, but the argument is kept for backwards compatibility.

The base (fallback) implementation makes multiple calls to draw_path. Backends may want to override this in order to render each set of path data only once, and then reference that path multiple times with the different offsets, colors, styles etc. The generator methods _iter_collection_raw_paths and _iter_collection are provided to help with (and standardize) the implementation across backends. It is highly recommended to use those generators, so that changes to the behavior of draw_path_collection can be made globally.

draw_quad_mesh(gc, master_transform, meshWidth, meshHeight, coordinates, offsets, offsetTrans, facecolors, antialiased, edgecolors)[source]#

Draw a quadmesh.

The base (fallback) implementation converts the quadmesh to paths and then calls draw_path_collection.

draw_tex(gc, x, y, s, prop, angle, *, mtext=None)[source]#

Draw a TeX instance.

Parameters:

gcGraphicsContextBase

The graphics context.

xfloat

The x location of the text in display coords.

yfloat

The y location of the text baseline in display coords.

sstr

The TeX text string.

propFontProperties

The font properties.

anglefloat

The rotation angle in degrees anti-clockwise.

mtextText

The original text object to be rendered.

draw_text(gc, x, y, s, prop, angle, ismath=False, mtext=None)[source]#

Draw a text instance.

Parameters:

gcGraphicsContextBase

The graphics context.

xfloat

The x location of the text in display coords.

yfloat

The y location of the text baseline in display coords.

sstr

The text string.

propFontProperties

The font properties.

anglefloat

The rotation angle in degrees anti-clockwise.

ismathbool or "TeX"

If True, use mathtext parser.

mtextText

The original text object to be rendered.

Notes

Notes for backend implementers:

RendererBase.draw_text also supports passing "TeX" to the ismath parameter to use TeX rendering, but this is not required for actual rendering backends, and indeed many builtin backends do not support this. Rather, TeX rendering is provided by draw_tex.

flipy()[source]#

Return whether y values increase from top to bottom.

Note that this only affects drawing of texts.

get_canvas_width_height()[source]#

Return the canvas width and height in display coords.

get_image_magnification()[source]#

Get the factor by which to magnify images passed to draw_image. Allows a backend to have images at a different resolution to other artists.

get_texmanager()[source]#

Return the TexManager instance.

get_text_width_height_descent(s, prop, ismath)[source]#

Get the width, height, and descent (offset from the bottom to the baseline), in display coords, of the string s with FontProperties prop.

Whitespace at the start and the end of s is included in the reported width.

new_gc()[source]#

Return an instance of a GraphicsContextBase.

open_group(s, gid=None)[source]#

Open a grouping element with label s and gid (if set) as id.

Only used by the SVG renderer.

option_image_nocomposite()[source]#

Return whether image composition by Matplotlib should be skipped.

Raster backends should usually return False (letting the C-level rasterizer take care of image composition); vector backends should usually return not rcParams["image.composite_image"].

option_scale_image()[source]#

Return whether arbitrary affine transformations in draw_image are supported (True for most vector backends).

points_to_pixels(points)[source]#

Convert points to display units.

You need to override this function (unless your backend doesn't have a dpi, e.g., postscript or svg). Some imaging systems assume some value for pixels per inch:

points to pixels = points * pixels_per_inch/72 * dpi/72

Parameters:

pointsfloat or array-like

Returns:

Points converted to pixels

start_filter()[source]#

Switch to a temporary renderer for image filtering effects.

Currently only supported by the agg renderer.

start_rasterizing()[source]#

Switch to the raster renderer.

Used by MixedModeRenderer.

stop_filter(filter_func)[source]#

Switch back to the original renderer. The contents of the temporary renderer is processed with the filter_func and is drawn on the original renderer as an image.

Currently only supported by the agg renderer.

stop_rasterizing()[source]#

Switch back to the vector renderer and draw the contents of the raster renderer as an image on the vector renderer.

Used by MixedModeRenderer.

class matplotlib.backend_bases.ResizeEvent(name, canvas)[source]#

Bases: Event

An event triggered by a canvas resize.

A ResizeEvent has a number of special attributes in addition to those defined by the parent Event class.

Attributes:

widthint

Width of the canvas in pixels.

heightint

Height of the canvas in pixels.

class matplotlib.backend_bases.ShowBase[source]#

Bases: _Backend

Simple base class to generate a show() function in backends.

Subclass must override mainloop() method.

class matplotlib.backend_bases.TimerBase(interval=None, callbacks=None)[source]#

Bases: object

A base class for providing timer events, useful for things animations. Backends need to implement a few specific methods in order to use their own timing mechanisms so that the timer events are integrated into their event loops.

Subclasses must override the following methods:

• _timer_start: Backend-specific code for starting the timer.

• _timer_stop: Backend-specific code for stopping the timer.

Subclasses may additionally override the following methods:

• _timer_set_single_shot: Code for setting the timer to single shot operating mode, if supported by the timer object. If not, the TimerBase class itself will store the flag and the _on_timer method should be overridden to support such behavior.

• _timer_set_interval: Code for setting the interval on the timer, if there is a method for doing so on the timer object.

• _on_timer: The internal function that any timer object should call, which will handle the task of running all callbacks that have been set.

Parameters:

intervalint, default: 1000ms

The time between timer events in milliseconds. Will be stored as timer.interval.

callbackslist[tuple[callable, tuple, dict]]

List of (func, args, kwargs) tuples that will be called upon timer events. This list is accessible as timer.callbacks and can be manipulated directly, or the functions add_callback and remove_callback can be used.

add_callback(func, *args, **kwargs)[source]#

Register func to be called by timer when the event fires. Any additional arguments provided will be passed to func.

This function returns func, which makes it possible to use it as a decorator.

property interval#

The time between timer events, in milliseconds.

remove_callback(func, *args, **kwargs)[source]#

Remove func from list of callbacks.

args and kwargs are optional and used to distinguish between copies of the same function registered to be called with different arguments. This behavior is deprecated. In the future, *args, **kwargs won't be considered anymore; to keep a specific callback removable by itself, pass it to add_callback as a functools.partial object.

property single_shot#

Whether this timer should stop after a single run.

start()[source]#

Start the timer.

stop()[source]#

Stop the timer.

class matplotlib.backend_bases.ToolContainerBase(toolmanager)[source]#

Bases: object

Base class for all tool containers, e.g. toolbars.

Attributes:

toolmanagerToolManager

The tools with which this ToolContainerBase wants to communicate.

add_tool(tool, group, position=-1)[source]#

Add a tool to this container.

Parameters:

tooltool_like

The tool to add, see ToolManager.get_tool.

groupstr

The name of the group to add this tool to.

positionint, default: -1

The position within the group to place this tool.

add_toolitem(name, group, position, image, description, toggle)[source]#

A hook to add a toolitem to the container.

This hook must be implemented in each backend and contains the backend-specific code to add an element to the toolbar.

Warning

This is part of the backend implementation and should not be called by end-users. They should instead call ToolContainerBase.add_tool.

The callback associated with the button click event must be exactly self.trigger_tool(name).

Parameters:

namestr

Name of the tool to add, this gets used as the tool's ID and as the default label of the buttons.

groupstr

Name of the group that this tool belongs to.

positionint

Position of the tool within its group, if -1 it goes at the end.

imagestr

Filename of the image for the button or None.

descriptionstr

Description of the tool, used for the tooltips.

togglebool

• True : The button is a toggle (change the pressed/unpressed state between consecutive clicks).

• False : The button is a normal button (returns to unpressed state after release).

remove_toolitem(name)[source]#

A hook to remove a toolitem from the container.

This hook must be implemented in each backend and contains the backend-specific code to remove an element from the toolbar; it is called when ToolManager emits a tool_removed_event.

Because some tools are present only on the ToolManager but not on the ToolContainerBase, this method must be a no-op when called on a tool absent from the container.

Warning

This is part of the backend implementation and should not be called by end-users. They should instead call ToolManager.remove_tool.

Parameters:

namestr

Name of the tool to remove.

set_message(s)[source]#

Display a message on the toolbar.

Parameters:

sstr

Message text.

toggle_toolitem(name, toggled)[source]#

A hook to toggle a toolitem without firing an event.

This hook must be implemented in each backend and contains the backend-specific code to silently toggle a toolbar element.

Warning

This is part of the backend implementation and should not be called by end-users. They should instead call ToolManager.trigger_tool or ToolContainerBase.trigger_tool (which are equivalent).

Parameters:

namestr

Id of the tool to toggle.

toggledbool

Whether to set this tool as toggled or not.

trigger_tool(name)[source]#

Trigger the tool.

Parameters:

namestr

Name (id) of the tool triggered from within the container.

matplotlib.backend_bases.button_press_handler(event, canvas=None, toolbar=None)[source]#

The default Matplotlib button actions for extra mouse buttons.

Parameters are as for key_press_handler, except that event is a MouseEvent.

matplotlib.backend_bases.get_registered_canvas_class(format)[source]#

Return the registered default canvas for given file format. Handles deferred import of required backend.

matplotlib.backend_bases.key_press_handler(event, canvas=None, toolbar=None)[source]#

Implement the default Matplotlib key bindings for the canvas and toolbar described at Navigation keyboard shortcuts.

Parameters:

eventKeyEvent

A key press/release event.

canvasFigureCanvasBase, default: event.canvas

The backend-specific canvas instance. This parameter is kept for back-compatibility, but, if set, should always be equal to event.canvas.

toolbarNavigationToolbar2, default: event.canvas.toolbar

The navigation cursor toolbar. This parameter is kept for back-compatibility, but, if set, should always be equal to event.canvas.toolbar.

matplotlib.backend_bases.register_backend(format, backend, description=None)[source]#

Register a backend for saving to a given file format.

Parameters:

formatstr

File extension

backendmodule string or canvas class

Backend for handling file output

descriptionstr, default: ""

Description of the file type.

matplotlib.backend_bases.scroll_handler(event, canvas=None, toolbar=None)[source]#