A module for dealing with the polylines used throughout matplotlib.
The primary class for polyline handling in matplotlib is Path. Almost all vector drawing makes use of Paths somewhere in the drawing pipeline.
Whilst a Path instance itself cannot be drawn, there exists Artist subclasses which can be used for convenient Path visualisation  the two most frequently used of these are PathPatch and PathCollection.
Bases: object
Path represents a series of possibly disconnected, possibly closed, line and curve segments.
These two arrays always have the same length in the first dimension. For example, to represent a cubic curve, you must provide three vertices as well as three codes CURVE3.
The code types are:
 STOP : 1 vertex (ignored)
A marker for the end of the entire path (currently not required and ignored)
 MOVETO : 1 vertex
Pick up the pen and move to the given vertex.
 LINETO : 1 vertex
Draw a line from the current position to the given vertex.
 CURVE3 : 1 control point, 1 endpoint
Draw a quadratic Bezier curve from the current position, with the given control point, to the given end point.
 CURVE4 : 2 control points, 1 endpoint
Draw a cubic Bezier curve from the current position, with the given control points, to the given end point.
 CLOSEPOLY : 1 vertex (ignored)
Draw a line segment to the start point of the current polyline.
Users of Path objects should not access the vertices and codes arrays directly. Instead, they should use iter_segments() or cleaned() to get the vertex/code pairs. This is important, since many Path objects, as an optimization, do not store a codes at all, but have a default one provided for them by iter_segments().
Note
The vertices and codes arrays should be treated as immutable – there are a number of optimizations and assumptions made up front in the constructor that will not change when the data changes.
Create a new path with the given vertices and codes.
Parameters:  vertices : array_like
codes : {None, array_like}, optional
_interpolation_steps : int, optional
closed : bool, optional
readonly : bool, optional


A dictionary mapping Path codes to the number of vertices that the code expects.
Return an arc on the unit circle from angle theta1 to angle theta2 (in degrees).
If n is provided, it is the number of spline segments to make. If n is not provided, the number of spline segments is determined based on the delta between theta1 and theta2.
Masionobe, L. 2003. Drawing an elliptical arc using polylines, quadratic or cubic Bezier curves.
Return a Path representing a circle of a given radius and center.
Parameters:  center : pair of floats
radius : float
readonly : bool


Notes
The circle is approximated using cubic Bezier curves. This uses 8 splines around the circle using the approach presented here:
Lancaster, Don. Approximating a Circle or an Ellipse Using Four Bezier Cubic Splines.
Cleans up the path according to the parameters returning a new Path instance.
See also
See iter_segments() for details of the keyword arguments.
Returns:  Path instance with cleaned up vertices and codes. : 

Clip the path to the given bounding box.
The path must be made up of one or more closed polygons. This algorithm will not behave correctly for unclosed paths.
If inside is True, clip to the inside of the box, otherwise to the outside of the box.
alias of uint8
The list of codes in the Path as a 1D numpy array. Each code is one of STOP, MOVETO, LINETO, CURVE3, CURVE4 or CLOSEPOLY. For codes that correspond to more than one vertex (CURVE3 and CURVE4), that code will be repeated so that the length of self.vertices and self.codes is always the same.
Returns True if this path completely contains the given path.
If transform is not None, the path will be transformed before performing the test.
Returns True if the path contains the given point.
If transform is not None, the path will be transformed before performing the test.
radius allows the path to be made slightly larger or smaller.
Returns a bool array which is True if the path contains the corresponding point.
If transform is not None, the path will be transformed before performing the test.
radius allows the path to be made slightly larger or smaller.
Returns a shallow copy of the Path, which will share the vertices and codes with the source Path.
Returns a deepcopy of the Path. The Path will not be readonly, even if the source Path is.
Returns the extents (xmin, ymin, xmax, ymax) of the path.
Unlike computing the extents on the vertices alone, this algorithm will take into account the curves and deal with control points appropriately.
True if the vertices array has nonfinite values.
Given a hatch specifier, hatchpattern, generates a Path that can be used in a repeated hatching pattern. density is the number of lines per unit square.
Returns a new path resampled to length N x steps. Does not currently handle interpolating curves.
Returns True if this path intersects a given Bbox.
filled, when True, treats the path as if it was filled. That is, if one path completely encloses the other, intersects_path() will return True.
Returns True if this path intersects another given path.
filled, when True, treats the paths as if they were filled. That is, if one path completely encloses the other, intersects_path() will return True.
Iterates over all of the curve segments in the path. Each iteration returns a 2tuple (vertices, code), where vertices is a sequence of 1  3 coordinate pairs, and code is one of the Path codes.
Additionally, this method can provide a number of standard cleanups and conversions to the path.
Parameters:  transform : None or Transform instance
remove_nans : {False, True}, optional
clip : None or sequence, optional
snap : None or bool, optional
stroke_width : float, optional
simplify : None or bool, optional
curves : {True, False}, optional
sketch : None or sequence, optional


Make a compound path from a list of Path objects.
Make a compound path object to draw a number of polygons with equal numbers of sides XY is a (numpolys x numsides x 2) numpy array of vertices. Return object is a Path
(Source code, png, hires.png, pdf)
True if the vertices array should be simplified.
The fraction of a pixel difference below which vertices will be simplified out.
Convert this path to a list of polygons. Each polygon is an Nx2 array of vertices. In other words, each polygon has no MOVETO instructions or curves. This is useful for displaying in backends that do not support compound paths or Bezier curves, such as GDK.
If width and height are both nonzero then the lines will be simplified so that vertices outside of (0, 0), (width, height) will be clipped.
Return a transformed copy of the path.
See also
Return the readonly Path of the unit circle.
For most cases, Path.circle() will be what you want.
Return a Path of the right half of a unit circle. The circle is approximated using cubic Bezier curves. This uses 4 splines around the circle using the approach presented here:
Lancaster, Don. Approximating a Circle or an Ellipse Using Four Bezier Cubic Splines.
Return a Path for a unit regular asterisk with the given numVertices and radius of 1.0, centered at (0, 0).
Return a Path instance for a unit regular polygon with the given numVertices and radius of 1.0, centered at (0, 0).
Return a Path for a unit regular star with the given numVertices and radius of 1.0, centered at (0, 0).
Return a wedge of the unit circle from angle theta1 to angle theta2 (in degrees).
If n is provided, it is the number of spline segments to make. If n is not provided, the number of spline segments is determined based on the delta between theta1 and theta2.
Deprecated since version 1.3: The cleanup_path function was deprecated in version 1.3. Use path.Path.cleaned instead.
cleanup_path(path, trans, remove_nans, clip, snap, simplify, curves, sketch_params)
Deprecated since version 1.3: The clip_path_to_rect function was deprecated in version 1.3. Use path.Path.clip_to_bbox instead.
clip_path_to_rect(path, bbox, inside)
Deprecated since version 1.3: The convert_path_to_polygons function was deprecated in version 1.3. Use path.Path.to_polygons instead.
convert_path_to_polygons(path, trans, width, height)
Given a sequence of Path objects, Transform objects and offsets, as found in a PathCollection, returns the bounding box that encapsulates all of them.
master_transform is a global transformation to apply to all paths
paths is a sequence of Path instances.
transforms is a sequence of Affine2D instances.
offsets is a sequence of (x, y) offsets (or an Nx2 array)
offset_transform is a Affine2D to apply to the offsets before applying the offset to the path.
The way that paths, transforms and offsets are combined follows the same method as for collections. Each is iterated over independently, so if you have 3 paths, 2 transforms and 1 offset, their combinations are as follows:
(A, A, A), (B, B, A), (C, A, A)
Deprecated since version 1.3: The get_path_extents function was deprecated in version 1.3. Use path.Path.get_extents instead.
get_path_extents(path, trans)
Given a sequence of Path objects and optional Transform objects, returns the bounding box that encapsulates all of them.
paths is a sequence of Path instances.
transforms is an optional sequence of Affine2D instances to apply to each path.
Deprecated since version 1.3: The path_in_path function was deprecated in version 1.3. Use path.Path.contains_path instead.
path_in_path(a, atrans, b, btrans)
Deprecated since version 1.3: The path_intersects_path function was deprecated in version 1.3. Use path.Path.intersects_path instead.
path_intersects_path(p1, p2)
Deprecated since version 1.3: The point_in_path function was deprecated in version 1.3. Use path.Path.contains_point instead.
point_in_path(x, y, path, trans)
Deprecated since version 1.3: The point_in_path_collection function was deprecated in version 1.3. Use collection.Collection.contains instead.
point_in_path_collection(x, y, r, trans, paths, transforms, offsets, offsetTrans, filled)
Deprecated since version 1.3: The points_in_path function was deprecated in version 1.3. Use path.Path.contains_points instead.
points_in_path(points, path, trans)