# projections

### matplotlib.projections

class matplotlib.projections.ProjectionRegistry

Bases: object

Manages the set of projections available to the system.

get_projection_class(name)

Get a projection class from its name.

get_projection_names()

Get a list of the names of all projections currently registered.

register(*projections)

Register a new set of projection(s).

matplotlib.projections.get_projection_class(projection=None)

Get a projection class from its name.

If projection is None, a standard rectilinear projection is returned.

matplotlib.projections.get_projection_names()

Get a list of acceptable projection names.

matplotlib.projections.process_projection_requirements(figure, *args, **kwargs)

(axes_proj_class, proj_class_kwargs, proj_stack_key)


Which can be used for new axes initialization/identification.

Note

kwargs is modified in place.

### matplotlib.projections.polar

class matplotlib.projections.polar.InvertedPolarTransform(axis=None, use_rmin=True)

Bases: matplotlib.transforms.Transform

The inverse of the polar transform, mapping Cartesian coordinate space x and y back to theta and r.

inverted()

Return the corresponding inverse transformation.

The return value of this method should be treated as temporary. An update to self does not cause a corresponding update to its inverted copy.

x === self.inverted().transform(self.transform(x))

transform_non_affine(xy)

Performs only the non-affine part of the transformation.

transform(values) is always equivalent to transform_affine(transform_non_affine(values)).

In non-affine transformations, this is generally equivalent to transform(values). In affine transformations, this is always a no-op.

Accepts a numpy array of shape (N x input_dims) and returns a numpy array of shape (N x output_dims).

Alternatively, accepts a numpy array of length input_dims and returns a numpy array of length output_dims.

class matplotlib.projections.polar.PolarAffine(scale_transform, limits)

Bases: matplotlib.transforms.Affine2DBase

The affine part of the polar projection. Scales the output so that maximum radius rests on the edge of the axes circle.

limits is the view limit of the data. The only part of its bounds that is used is ymax (for the radius maximum). The theta range is always fixed to (0, 2pi).

get_matrix()

Get the Affine transformation array for the affine part of this transform.

class matplotlib.projections.polar.PolarAxes(*args, **kwargs)

Bases: matplotlib.axes._axes.Axes

A polar graph projection, where the input dimensions are theta, r.

Theta starts pointing east and goes anti-clockwise.

class InvertedPolarTransform(axis=None, use_rmin=True)

Bases: matplotlib.transforms.Transform

The inverse of the polar transform, mapping Cartesian coordinate space x and y back to theta and r.

inverted()

Return the corresponding inverse transformation.

The return value of this method should be treated as temporary. An update to self does not cause a corresponding update to its inverted copy.

x === self.inverted().transform(self.transform(x))

transform_non_affine(xy)

Performs only the non-affine part of the transformation.

transform(values) is always equivalent to transform_affine(transform_non_affine(values)).

In non-affine transformations, this is generally equivalent to transform(values). In affine transformations, this is always a no-op.

Accepts a numpy array of shape (N x input_dims) and returns a numpy array of shape (N x output_dims).

Alternatively, accepts a numpy array of length input_dims and returns a numpy array of length output_dims.

class PolarAxes.PolarAffine(scale_transform, limits)

Bases: matplotlib.transforms.Affine2DBase

The affine part of the polar projection. Scales the output so that maximum radius rests on the edge of the axes circle.

limits is the view limit of the data. The only part of its bounds that is used is ymax (for the radius maximum). The theta range is always fixed to (0, 2pi).

get_matrix()

Get the Affine transformation array for the affine part of this transform.

class PolarAxes.PolarTransform(axis=None, use_rmin=True)

Bases: matplotlib.transforms.Transform

The base polar transform. This handles projection theta and r into Cartesian coordinate space x and y, but does not perform the ultimate affine transformation into the correct position.

inverted()

Return the corresponding inverse transformation.

The return value of this method should be treated as temporary. An update to self does not cause a corresponding update to its inverted copy.

x === self.inverted().transform(self.transform(x))

transform_non_affine(tr)

Performs only the non-affine part of the transformation.

transform(values) is always equivalent to transform_affine(transform_non_affine(values)).

In non-affine transformations, this is generally equivalent to transform(values). In affine transformations, this is always a no-op.

Accepts a numpy array of shape (N x input_dims) and returns a numpy array of shape (N x output_dims).

Alternatively, accepts a numpy array of length input_dims and returns a numpy array of length output_dims.

transform_path_non_affine(path)

Returns a path, transformed only by the non-affine part of this transform.

path: a Path instance.

transform_path(path) is equivalent to transform_path_affine(transform_path_non_affine(values)).

class PolarAxes.RadialLocator(base)

Ensures that all ticks are strictly positive. For all other tasks, it delegates to the base Locator (which may be different depending on the scale of the r-axis.

class PolarAxes.ThetaFormatter

Used to format the theta tick labels. Converts the native unit of radians into degrees and adds a degree symbol.

PolarAxes.can_pan()

Return True if this axes supports the pan/zoom button functionality.

For polar axes, this is slightly misleading. Both panning and zooming are performed by the same button. Panning is performed in azimuth while zooming is done along the radial.

PolarAxes.can_zoom()

Return True if this axes supports the zoom box button functionality.

Polar axes do not support zoom boxes.

PolarAxes.format_coord(theta, r)

Return a format string formatting the coordinate using Unicode characters.

PolarAxes.get_data_ratio()

Return the aspect ratio of the data itself. For a polar plot, this should always be 1.0

PolarAxes.get_rlabel_position()
Returns: float The theta position of the radius labels in degrees.
PolarAxes.get_theta_direction()

Get the direction in which theta increases.

-1:
Theta increases in the clockwise direction
1:
Theta increases in the counterclockwise direction
PolarAxes.get_theta_offset()

Get the offset for the location of 0 in radians.

PolarAxes.set_rgrids(radii, labels=None, angle=None, fmt=None, **kwargs)

Set the radial locations and labels of the r grids.

The labels will appear at radial distances radii at the given angle in degrees.

labels, if not None, is a len(radii) list of strings of the labels to use at each radius.

If labels is None, the built-in formatter will be used.

Return value is a list of tuples (line, label), where line is Line2D instances and the label is Text instances.

kwargs are optional text properties for the labels:

Property Description
agg_filter unknown
alpha float (0.0 transparent through 1.0 opaque)
animated [True | False]
axes an Axes instance
backgroundcolor any matplotlib color
bbox FancyBboxPatch prop dict
clip_box a matplotlib.transforms.Bbox instance
clip_on [True | False]
clip_path [ (Path, Transform) | Patch | None ]
color any matplotlib color
contains a callable function
family or fontname or fontfamily or name [FONTNAME | ?serif? | ?sans-serif? | ?cursive? | ?fantasy? | ?monospace? ]
figure a matplotlib.figure.Figure instance
fontproperties or font_properties a matplotlib.font_manager.FontProperties instance
gid an id string
horizontalalignment or ha [ ?center? | ?right? | ?left? ]
label string or anything printable with ?%s? conversion.
linespacing float (multiple of font size)
multialignment [?left? | ?right? | ?center? ]
path_effects unknown
picker [None|float|boolean|callable]
position (x,y)
rasterized [True | False | None]
rotation [ angle in degrees | ?vertical? | ?horizontal? ]
rotation_mode unknown
size or fontsize [size in points | ?xx-small? | ?x-small? | ?small? | ?medium? | ?large? | ?x-large? | ?xx-large? ]
sketch_params unknown
snap unknown
stretch or fontstretch [a numeric value in range 0-1000 | ?ultra-condensed? | ?extra-condensed? | ?condensed? | ?semi-condensed? | ?normal? | ?semi-expanded? | ?expanded? | ?extra-expanded? | ?ultra-expanded? ]
style or fontstyle [ ?normal? | ?italic? | ?oblique?]
text string or anything printable with ?%s? conversion.
transform Transform instance
url a url string
usetex unknown
variant or fontvariant [ ?normal? | ?small-caps? ]
verticalalignment or ma or va [ ?center? | ?top? | ?bottom? | ?baseline? ]
visible [True | False]
weight or fontweight [a numeric value in range 0-1000 | ?ultralight? | ?light? | ?normal? | ?regular? | ?book? | ?medium? | ?roman? | ?semibold? | ?demibold? | ?demi? | ?bold? | ?heavy? | ?extra bold? | ?black? ]
wrap unknown
x float
y float
zorder any number

ACCEPTS: sequence of floats

PolarAxes.set_rlabel_position(value)

Parameters: value : number The angular position of the radius labels in degrees.
PolarAxes.set_theta_direction(direction)

Set the direction in which theta increases.

clockwise, -1:
Theta increases in the clockwise direction
counterclockwise, anticlockwise, 1:
Theta increases in the counterclockwise direction
PolarAxes.set_theta_offset(offset)

Set the offset for the location of 0 in radians.

PolarAxes.set_theta_zero_location(loc)

Sets the location of theta?s zero. (Calls set_theta_offset with the correct value in radians under the hood.)

May be one of ?N?, ?NW?, ?W?, ?SW?, ?S?, ?SE?, ?E?, or ?NE?.

PolarAxes.set_thetagrids(angles, labels=None, frac=None, fmt=None, **kwargs)

Set the angles at which to place the theta grids (these gridlines are equal along the theta dimension). angles is in degrees.

labels, if not None, is a len(angles) list of strings of the labels to use at each angle.

If labels is None, the labels will be fmt % angle

frac is the fraction of the polar axes radius at which to place the label (1 is the edge). e.g., 1.05 is outside the axes and 0.95 is inside the axes.

Return value is a list of tuples (line, label), where line is Line2D instances and the label is Text instances.

kwargs are optional text properties for the labels:

Property Description
agg_filter unknown
alpha float (0.0 transparent through 1.0 opaque)
animated [True | False]
axes an Axes instance
backgroundcolor any matplotlib color
bbox FancyBboxPatch prop dict
clip_box a matplotlib.transforms.Bbox instance
clip_on [True | False]
clip_path [ (Path, Transform) | Patch | None ]
color any matplotlib color
contains a callable function
family or fontname or fontfamily or name [FONTNAME | ?serif? | ?sans-serif? | ?cursive? | ?fantasy? | ?monospace? ]
figure a matplotlib.figure.Figure instance
fontproperties or font_properties a matplotlib.font_manager.FontProperties instance
gid an id string
horizontalalignment or ha [ ?center? | ?right? | ?left? ]
label string or anything printable with ?%s? conversion.
linespacing float (multiple of font size)
multialignment [?left? | ?right? | ?center? ]
path_effects unknown
picker [None|float|boolean|callable]
position (x,y)
rasterized [True | False | None]
rotation [ angle in degrees | ?vertical? | ?horizontal? ]
rotation_mode unknown
size or fontsize [size in points | ?xx-small? | ?x-small? | ?small? | ?medium? | ?large? | ?x-large? | ?xx-large? ]
sketch_params unknown
snap unknown
stretch or fontstretch [a numeric value in range 0-1000 | ?ultra-condensed? | ?extra-condensed? | ?condensed? | ?semi-condensed? | ?normal? | ?semi-expanded? | ?expanded? | ?extra-expanded? | ?ultra-expanded? ]
style or fontstyle [ ?normal? | ?italic? | ?oblique?]
text string or anything printable with ?%s? conversion.
transform Transform instance
url a url string
usetex unknown
variant or fontvariant [ ?normal? | ?small-caps? ]
verticalalignment or ma or va [ ?center? | ?top? | ?bottom? | ?baseline? ]
visible [True | False]
weight or fontweight [a numeric value in range 0-1000 | ?ultralight? | ?light? | ?normal? | ?regular? | ?book? | ?medium? | ?roman? | ?semibold? | ?demibold? | ?demi? | ?bold? | ?heavy? | ?extra bold? | ?black? ]
wrap unknown
x float
y float
zorder any number

ACCEPTS: sequence of floats

class matplotlib.projections.polar.PolarTransform(axis=None, use_rmin=True)

Bases: matplotlib.transforms.Transform

The base polar transform. This handles projection theta and r into Cartesian coordinate space x and y, but does not perform the ultimate affine transformation into the correct position.

inverted()

Return the corresponding inverse transformation.

The return value of this method should be treated as temporary. An update to self does not cause a corresponding update to its inverted copy.

x === self.inverted().transform(self.transform(x))

transform_non_affine(tr)

Performs only the non-affine part of the transformation.

transform(values) is always equivalent to transform_affine(transform_non_affine(values)).

In non-affine transformations, this is generally equivalent to transform(values). In affine transformations, this is always a no-op.

Accepts a numpy array of shape (N x input_dims) and returns a numpy array of shape (N x output_dims).

Alternatively, accepts a numpy array of length input_dims and returns a numpy array of length output_dims.

transform_path_non_affine(path)

Returns a path, transformed only by the non-affine part of this transform.

path: a Path instance.

transform_path(path) is equivalent to transform_path_affine(transform_path_non_affine(values)).

class matplotlib.projections.polar.RadialLocator(base)

Ensures that all ticks are strictly positive. For all other tasks, it delegates to the base Locator (which may be different depending on the scale of the r-axis.
class matplotlib.projections.polar.ThetaFormatter