matplotlib.backends.backend_svg#

matplotlib.backends.backend_svg.FigureCanvas[source]#

alias of FigureCanvasSVG

class matplotlib.backends.backend_svg.FigureCanvasSVG(figure=None)[source]#

Bases: FigureCanvasBase

draw()[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.

filetypes = {'svg': 'Scalable Vector Graphics', 'svgz': 'Scalable Vector Graphics'}#

fixed_dpi = 72#

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.

print_svg(filename, *, bbox_inches_restore=None, metadata=None)[source]#

Parameters:

filenamestr or path-like or file-like

Output target; if a string, a file will be opened for writing.

metadatadict[str, Any], optional

Metadata in the SVG file defined as key-value pairs of strings, datetimes, or lists of strings, e.g., {'Creator': 'My software', 'Contributor': ['Me', 'My Friend'], 'Title': 'Awesome'}.

The standard keys and their value types are:

• str: 'Coverage', 'Description', 'Format', 'Identifier', 'Language', 'Relation', 'Source', 'Title', and 'Type'.

• str or list of str: 'Contributor', 'Creator', 'Keywords', 'Publisher', and 'Rights'.

• str, date, datetime, or tuple of same: 'Date'. If a non-str, then it will be formatted as ISO 8601.

Values have been predefined for 'Creator', 'Date', 'Format', and 'Type'. They can be removed by setting them to None.

Information is encoded as Dublin Core Metadata.

print_svgz(filename, **kwargs)[source]#

class matplotlib.backends.backend_svg.RendererSVG(width, height, svgwriter, basename=None, image_dpi=72, *, metadata=None)[source]#

Bases: RendererBase

close_blend_group()[source]#

Close the transparency group used for blending.

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_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.

finalize()[source]#

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_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.

open_blend_group(blend_mode, *, alpha=1, knockout=False)[source]#

Open a transparency group used for blending.

This blend group can be an isolated group, a knockout group, both, or neither. See Blending and compositing groups of artists for details, and see also Blending and compositing artists.

Isolated groups are supported by the Agg, Cairo, PDF, PGF, and SVG renderers:

• If blend_mode is not None, this blend group is an isolated group. Artists within this group are rendered in an separate buffer. When this group is closed, the isolated buffer is then drawn as an image into the primary buffer using the specified blend mode and scalar alpha.

• If blend_mode is None, this blend group is a non-isolated group. Artists within this group are rendered successively onto the primary buffer, which has the same result as if the artists were not grouped unless this group is a knockout group.

Knockout groups are supported by the Agg, Cairo, PDF, and PGF renderers:

• If knockout is False, the blend group is a non-knockout group. Each successive artist in this group is rendered onto the backdrop as modified by the preceding artists in this group.

• If knockout is True, the blend group is a knockout group. Each successive artist in this group is rendered onto the initial backdrop, ignoring any modifications underneath by preceding artists in this group.

• If the knockout group is also isolated, the initial backdrop is a fully transparent buffer.

• If the knockout group is not isolated, the initial backdrop is the primary buffer. This is supported by the PDF and PGF renderers, but not by the Agg and Cairo renderers.

Parameters:

blend_modeblend mode or None

If None, this group is a non-isolated group. Otherwise, this group is an isolated group that will be rendered into the primary buffer using this blend mode.

alphafloat, default: 1

The scalar alpha to additionally apply to the isolated buffer when blending into the primary buffer. Defaults to 1, which means no fading of the isolated buffer.

knockoutbool, default: False

Specifies whether this group is a knockout group. Defaults to False, which means this group is a non-knockout group.

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).