Python 中的交互式 BSpline 拟合
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【中文标题】Python 中的交互式 BSpline 拟合【英文标题】：Interactive BSpline fitting in Python 【发布时间】：2018-09-09 06:05:47 【问题描述】：使用以下函数，可以在输入点 P 上拟合三次样条：
def plotCurve(P):
pts = np.vstack([P, P[0]])
x, y = pts.T
i = np.arange(len(pts))
interp_i = np.linspace(0, i.max(), 100000 * i.max())
xi = interp1d(i, x, kind='cubic')(interp_i)
yi = interp1d(i, y, kind='cubic')(interp_i)
fig, ax = plt.subplots()
fig,ax=plt.subplots()
ax.plot(xi, yi)
ax.plot(x, y, 'ko')
#plt.show()
return xi,yi
输入点P可以是以下形式：
P=[(921,1181),(951,1230),(993,1243),(1035,1230),
(1065,1181),(1045,1130),(993,1130),(945,1130)]
现在，我想让 P 的这些点可拖动，这样当我们改变任何点的位置时，样条线就会重新安装在新点上。
以此作为参考：https://matplotlib.org/1.4.3/examples/event_handling/poly_editor.html（matplotlib 中的事件处理），我有以下代码：
"""
This is an example to show how to build cross-GUI applications using
matplotlib event handling to interact with objects on the canvas
"""
import numpy as np
from matplotlib.lines import Line2D
from matplotlib.artist import Artist
from matplotlib.mlab import dist_point_to_segment
class PolygonInteractor:
"""
An polygon editor.
Key-bindings
't' toggle vertex markers on and off. When vertex markers are on,
you can move them, delete them
'd' delete the vertex under point
'i' insert a vertex at point. You must be within epsilon of the
line connecting two existing vertices
"""
showverts = True
epsilon = 5 # max pixel distance to count as a vertex hit
def __init__(self, ax, poly):
if poly.figure is None:
raise RuntimeError('You must first add the polygon to a figure or canvas before defining the interactor')
self.ax = ax
canvas = poly.figure.canvas
self.poly = poly
x, y = zip(*self.poly.xy)
self.line = Line2D(x, y, marker='o', markerfacecolor='r', animated=True)
self.ax.add_line(self.line)
#self._update_line(poly)
cid = self.poly.add_callback(self.poly_changed)
self._ind = None # the active vert
canvas.mpl_connect('draw_event', self.draw_callback)
canvas.mpl_connect('button_press_event', self.button_press_callback)
canvas.mpl_connect('key_press_event', self.key_press_callback)
canvas.mpl_connect('button_release_event', self.button_release_callback)
canvas.mpl_connect('motion_notify_event', self.motion_notify_callback)
self.canvas = canvas
def draw_callback(self, event):
self.background = self.canvas.copy_from_bbox(self.ax.bbox)
self.ax.draw_artist(self.poly)
self.ax.draw_artist(self.line)
self.canvas.blit(self.ax.bbox)
def poly_changed(self, poly):
'this method is called whenever the polygon object is called'
# only copy the artist props to the line (except visibility)
vis = self.line.get_visible()
Artist.update_from(self.line, poly)
self.line.set_visible(vis) # don't use the poly visibility state
def get_ind_under_point(self, event):
'get the index of the vertex under point if within epsilon tolerance'
# display coords
xy = np.asarray(self.poly.xy)
xyt = self.poly.get_transform().transform(xy)
xt, yt = xyt[:, 0], xyt[:, 1]
d = np.sqrt((xt-event.x)**2 + (yt-event.y)**2)
indseq = np.nonzero(np.equal(d, np.amin(d)))[0]
ind = indseq[0]
if d[ind]>=self.epsilon:
ind = None
return ind
def button_press_callback(self, event):
'whenever a mouse button is pressed'
if not self.showverts: return
if event.inaxes==None: return
if event.button != 1: return
self._ind = self.get_ind_under_point(event)
def button_release_callback(self, event):
'whenever a mouse button is released'
if not self.showverts: return
if event.button != 1: return
self._ind = None
def key_press_callback(self, event):
'whenever a key is pressed'
if not event.inaxes: return
if event.key=='t':
self.showverts = not self.showverts
self.line.set_visible(self.showverts)
if not self.showverts: self._ind = None
elif event.key=='d':
ind = self.get_ind_under_point(event)
if ind is not None:
self.poly.xy = [tup for i,tup in enumerate(self.poly.xy) if i!=ind]
self.line.set_data(zip(*self.poly.xy))
elif event.key=='i':
xys = self.poly.get_transform().transform(self.poly.xy)
p = event.x, event.y # display coords
for i in range(len(xys)-1):
s0 = xys[i]
s1 = xys[i+1]
d = dist_point_to_segment(p, s0, s1)
if d<=self.epsilon:
self.poly.xy = np.array(
list(self.poly.xy[:i]) +
[(event.xdata, event.ydata)] +
list(self.poly.xy[i:]))
self.line.set_data(zip(*self.poly.xy))
break
self.canvas.draw()
def motion_notify_callback(self, event):
'on mouse movement'
if not self.showverts: return
if self._ind is None: return
if event.inaxes is None: return
if event.button != 1: return
x,y = event.xdata, event.ydata
self.poly.xy[self._ind] = x,y
self.line.set_data(zip(*self.poly.xy))
self.canvas.restore_region(self.background)
self.ax.draw_artist(self.poly)
self.ax.draw_artist(self.line)
self.canvas.blit(self.ax.bbox)
if __name__ == '__main__':
import matplotlib.pyplot as plt
from matplotlib.patches import Polygon
#theta = np.arange(0, 2*np.pi, 0.1)
#r = 1.5
#xs = r*np.cos(theta)
#ys = r*np.sin(theta)
xs = (921, 951, 993, 1035, 1065, 1045, 993, 945)
ys = (1181, 1230, 1243, 1230, 1181, 1130, 1130, 1130)
poly = Polygon(list(zip(xs, ys)), animated=True)
fig, ax = plt.subplots()
ax.add_patch(poly)
p = PolygonInteractor(ax, poly)
#ax.add_line(p.line)
ax.set_title('Click and drag a point to move it')
#ax.set_xlim((-2,2))
#ax.set_ylim((-2,2))
ax.set_xlim((800, 1300))
ax.set_ylim((1000, 1300))
plt.show()
现在，我想做的是用我的样条拟合函数替换多边形拟合。因为我是新手，所以我不知道该怎么做。 有没有办法保持所有相同的功能，但只通过给定点拟合样条而不是多边形，使其交互并根据点移动重新拟合样条？
我的样条线看起来有点像这样：
我该怎么做呢？
或者，如果有其他合适的方法可以达到同样的效果，请推荐。
也欢迎使用 MATLAB 提出建议。
【问题讨论】：
这肯定是可能的。既然你有你的拟合功能和交互功能，那么在组合它们时你会遇到什么问题？ @ImportanceOfBeingErnest 因为我不熟悉这些函数，所以我无法用我自己的函数替换 poly.figure.canvas 创建的部分。你能帮我把两者结合起来吗？ @ImportanceOfBeingErnest 显然某些正在使用的功能仅适用于 poly.figure？我不能为我的三次样条扩展 _update_line 等吗？？dist_point_to_segment 已从 mlab 中删除，但可以从此处复制源代码和 dist 函数：matplotlib.org/3.0.0/_modules/matplotlib/…
【参考方案1】：
当然你需要将你的函数添加到PolygonInteractor。不要让它自己画任何东西。
然后在类中添加一个新行，self.line2，这将是要更新的行。
最后，让全班也画出你的新线。并使用插值函数的结果对其进行更新。
为方便起见，您可以使多边形 (self.poly) 不可见，同时从 self.line 中删除线并仅显示点可能有意义。
import numpy as np
from scipy.interpolate import interp1d
from matplotlib.lines import Line2D
from matplotlib.artist import Artist
from matplotlib.mlab import dist_point_to_segment
class PolygonInteractor(object):
"""
A polygon editor.
https://matplotlib.org/gallery/event_handling/poly_editor.html
Key-bindings
't' toggle vertex markers on and off. When vertex markers are on,
you can move them, delete them
'd' delete the vertex under point
'i' insert a vertex at point. You must be within epsilon of the
line connecting two existing vertices
"""
showverts = True
epsilon = 5 # max pixel distance to count as a vertex hit
def __init__(self, ax, poly, visible=False):
if poly.figure is None:
raise RuntimeError('You must first add the polygon to a figure '
'or canvas before defining the interactor')
self.ax = ax
canvas = poly.figure.canvas
self.poly = poly
self.poly.set_visible(visible)
x, y = zip(*self.poly.xy)
self.line = Line2D(x, y, ls="",
marker='o', markerfacecolor='r',
animated=True)
self.ax.add_line(self.line)
self.cid = self.poly.add_callback(self.poly_changed)
self._ind = None # the active vert
canvas.mpl_connect('draw_event', self.draw_callback)
canvas.mpl_connect('button_press_event', self.button_press_callback)
canvas.mpl_connect('key_press_event', self.key_press_callback)
canvas.mpl_connect('button_release_event', self.button_release_callback)
canvas.mpl_connect('motion_notify_event', self.motion_notify_callback)
self.canvas = canvas
x,y = self.interpolate()
self.line2 = Line2D(x, y, animated=True)
self.ax.add_line(self.line2)
def interpolate(self):
x, y = self.poly.xy[:].T
i = np.arange(len(x))
interp_i = np.linspace(0, i.max(), 100 * i.max())
xi = interp1d(i, x, kind='cubic')(interp_i)
yi = interp1d(i, y, kind='cubic')(interp_i)
return xi,yi
def draw_callback(self, event):
self.background = self.canvas.copy_from_bbox(self.ax.bbox)
self.ax.draw_artist(self.poly)
self.ax.draw_artist(self.line)
self.ax.draw_artist(self.line2)
# do not need to blit here, this will fire before the screen is
# updated
def poly_changed(self, poly):
'this method is called whenever the polygon object is called'
# only copy the artist props to the line (except visibility)
vis = self.line.get_visible()
Artist.update_from(self.line, poly)
self.line.set_visible(vis) # don't use the poly visibility state
def get_ind_under_point(self, event):
'get the index of the vertex under point if within epsilon tolerance'
# display coords
xy = np.asarray(self.poly.xy)
xyt = self.poly.get_transform().transform(xy)
xt, yt = xyt[:, 0], xyt[:, 1]
d = np.hypot(xt - event.x, yt - event.y)
indseq, = np.nonzero(d == d.min())
ind = indseq[0]
if d[ind] >= self.epsilon:
ind = None
return ind
def button_press_callback(self, event):
'whenever a mouse button is pressed'
if not self.showverts:
return
if event.inaxes is None:
return
if event.button != 1:
return
self._ind = self.get_ind_under_point(event)
def button_release_callback(self, event):
'whenever a mouse button is released'
if not self.showverts:
return
if event.button != 1:
return
self._ind = None
def key_press_callback(self, event):
'whenever a key is pressed'
if not event.inaxes:
return
if event.key == 't':
self.showverts = not self.showverts
self.line.set_visible(self.showverts)
if not self.showverts:
self._ind = None
elif event.key == 'd':
ind = self.get_ind_under_point(event)
if ind is not None:
self.poly.xy = np.delete(self.poly.xy,
ind, axis=0)
self.line.set_data(zip(*self.poly.xy))
elif event.key == 'i':
xys = self.poly.get_transform().transform(self.poly.xy)
p = event.x, event.y # display coords
for i in range(len(xys) - 1):
s0 = xys[i]
s1 = xys[i + 1]
d = dist_point_to_segment(p, s0, s1)
if d <= self.epsilon:
self.poly.xy = np.insert(
self.poly.xy, i+1,
[event.xdata, event.ydata],
axis=0)
self.line.set_data(zip(*self.poly.xy))
break
if self.line.stale:
self.canvas.draw_idle()
def motion_notify_callback(self, event):
'on mouse movement'
if not self.showverts:
return
if self._ind is None:
return
if event.inaxes is None:
return
if event.button != 1:
return
x, y = event.xdata, event.ydata
self.poly.xy[self._ind] = x, y
if self._ind == 0:
self.poly.xy[-1] = x, y
elif self._ind == len(self.poly.xy) - 1:
self.poly.xy[0] = x, y
self.line.set_data(zip(*self.poly.xy))
x,y = self.interpolate()
self.line2.set_data(x,y)
self.canvas.restore_region(self.background)
self.ax.draw_artist(self.poly)
self.ax.draw_artist(self.line)
self.ax.draw_artist(self.line2)
self.canvas.blit(self.ax.bbox)
if __name__ == '__main__':
import matplotlib.pyplot as plt
from matplotlib.patches import Polygon
#theta = np.arange(0, 2*np.pi, 0.1)
#r = 1.5
#xs = r*np.cos(theta)
#ys = r*np.sin(theta)
xs = (921, 951, 993, 1035, 1065, 1045, 993, 945)
ys = (1181, 1230, 1243, 1230, 1181, 1130, 1130, 1130)
poly = Polygon(list(zip(xs, ys)), animated=True)
fig, ax = plt.subplots()
ax.add_patch(poly)
p = PolygonInteractor(ax, poly, visible=False)
ax.set_title('Click and drag a point to move it')
ax.set_xlim((800, 1300))
ax.set_ylim((1000, 1300))
plt.show()
请注意，此处创建的曲线并不是真正的循环。它有一个曲线不是很平滑的起点。这可以通过使用一组真正循环的贝塞尔曲线来规避，如Create random shape/contour using matplotlib 所示。
【讨论】：
非常感谢！我现在知道该怎么做。如果我还想动态计算曲线的长度（检查函数的编辑）并在我们移动点时将其与图形一起显示，该怎么做？ @ImportanceOfBeingErnest 我建议您在回答完问题后不要修改。如何更改轴中的某些文本的问题肯定已经在其他地方得到了答案。 您好，我正在搜索 gui 曲线以正常化值，如 photoshop、3d 程序......任何帮助 Reggards。 ***.com/questions/63537721/…你的例子很可爱 部分导入现已弃用，PolygonInteractor 应根据此修改：matplotlib.org/stable/gallery/event_handling/…【参考方案2】：
对@ImportanceOfBeingErnest 的答案进行更新和一些改进。 matplotlib 不再支持dist_point_to_segment，应根据新的docs 相应地修改类。
除此之外，我认为对于样条曲线也具有点插入功能可能很有用，这实际上是缺失的。由于曲线的点控制只能添加到直线上，所以我用虚线样式使它可见。可以使用“t”按钮切换此行的可见性。 interpolate 函数现在更一般地在类外部定义，并且可以在声明时直接设置多边形的可见属性，而不是在类内部修改它。通过这种方式，类结果更干净，修改更少。这是我的结果和代码：
"""
===========
Poly Editor
===========
This is an example to show how to build cross-GUI applications using
Matplotlib event handling to interact with objects on the canvas.
"""
import numpy as np
from scipy.interpolate import interp1d
from matplotlib.lines import Line2D
from matplotlib.artist import Artist
def dist(x, y):
"""
Return the distance between two points.
"""
d = x - y
return np.sqrt(np.dot(d, d))
def dist_point_to_segment(p, s0, s1):
"""
Get the distance of a point to a segment.
*p*, *s0*, *s1* are *xy* sequences
This algorithm from
http://geomalgorithms.com/a02-_lines.html
"""
v = s1 - s0
w = p - s0
c1 = np.dot(w, v)
if c1 <= 0:
return dist(p, s0)
c2 = np.dot(v, v)
if c2 <= c1:
return dist(p, s1)
b = c1 / c2
pb = s0 + b * v
return dist(p, pb)
def interpolate(x, y):
x, y = x, y##self.poly.xy[:].T
i = np.arange(len(x))
interp_i = np.linspace(0, i.max(), 100 * i.max())
xi = interp1d(i, x, kind='cubic')(interp_i)
yi = interp1d(i, y, kind='cubic')(interp_i)
return xi,yi
class PolygonInteractor:
"""
A polygon editor.
Key-bindings
't' toggle vertex markers on and off. When vertex markers are on,
you can move them, delete them
'd' delete the vertex under point
'i' insert a vertex at point. You must be within epsilon of the
line connecting two existing vertices
"""
showverts = True
epsilon = 5 # max pixel distance to count as a vertex hit
def __init__(self, ax, poly):
if poly.figure is None:
raise RuntimeError('You must first add the polygon to a figure '
'or canvas before defining the interactor')
self.ax = ax
canvas = poly.figure.canvas
self.poly = poly
x, y = zip(*self.poly.xy)
self.line = Line2D(x, y, ls = '--',
marker='o', markerfacecolor='r',
animated=True)
self.ax.add_line(self.line)
xs, ys = self.poly.xy[:].T
xs, ys = interpolate(xs, ys)
self.spline = Line2D(xs, ys, animated = True)
self.ax.add_line(self.spline)
self.cid = self.poly.add_callback(self.poly_changed)
self._ind = None # the active vert
canvas.mpl_connect('draw_event', self.on_draw)
canvas.mpl_connect('button_press_event', self.on_button_press)
canvas.mpl_connect('key_press_event', self.on_key_press)
canvas.mpl_connect('button_release_event', self.on_button_release)
canvas.mpl_connect('motion_notify_event', self.on_mouse_move)
self.canvas = canvas
def on_draw(self, event):
self.background = self.canvas.copy_from_bbox(self.ax.bbox)
self.ax.draw_artist(self.poly)
self.ax.draw_artist(self.line)
self.ax.draw_artist(self.spline)
# do not need to blit here, this will fire before the screen is
# updated
def poly_changed(self, poly):
"""This method is called whenever the pathpatch object is called."""
# only copy the artist props to the line (except visibility)
vis = self.line.get_visible()
Artist.update_from(self.line, poly)
self.line.set_visible(vis) # don't use the poly visibility state
def get_ind_under_point(self, event):
"""
Return the index of the point closest to the event position or *None*
if no point is within ``self.epsilon`` to the event position.
"""
# display coords
xy = np.asarray(self.poly.xy)
xyt = self.poly.get_transform().transform(xy)
xt, yt = xyt[:, 0], xyt[:, 1]
d = np.hypot(xt - event.x, yt - event.y)
indseq, = np.nonzero(d == d.min())
ind = indseq[0]
if d[ind] >= self.epsilon:
ind = None
return ind
def on_button_press(self, event):
"""Callback for mouse button presses."""
if not self.showverts:
return
if event.inaxes is None:
return
if event.button != 1:
return
self._ind = self.get_ind_under_point(event)
def on_button_release(self, event):
"""Callback for mouse button releases."""
if not self.showverts:
return
if event.button != 1:
return
self._ind = None
def on_key_press(self, event):
"""Callback for key presses."""
if not event.inaxes:
return
if event.key == 't':
self.showverts = not self.showverts
self.line.set_visible(self.showverts)
if not self.showverts:
self._ind = None
elif event.key == 'd':
ind = self.get_ind_under_point(event)
if ind is not None:
self.poly.xy = np.delete(self.poly.xy,
ind, axis=0)
self.line.set_data(zip(*self.poly.xy))
elif event.key == 'i':
xys = self.poly.get_transform().transform(self.poly.xy)
p = event.x, event.y # display coords
for i in range(len(xys) - 1):
s0 = xys[i]
s1 = xys[i + 1]
d = dist_point_to_segment(p, s0, s1)
if d <= self.epsilon:
self.poly.xy = np.insert(
self.poly.xy, i+1,
[event.xdata, event.ydata],
axis=0)
self.line.set_data(zip(*self.poly.xy))
xs, ys = self.poly.xy[:].T
xs, ys = interpolate(xs, ys)
self.spline.set_data(xs, ys)
break
if self.line.stale:
self.canvas.draw_idle()
def on_mouse_move(self, event):
"""Callback for mouse movements."""
if not self.showverts:
return
if self._ind is None:
return
if event.inaxes is None:
return
if event.button != 1:
return
x, y = event.xdata, event.ydata
self.poly.xy[self._ind] = x, y
if self._ind == 0:
self.poly.xy[-1] = x, y
elif self._ind == len(self.poly.xy) - 1:
self.poly.xy[0] = x, y
self.line.set_data(zip(*self.poly.xy))
xs, ys = self.poly.xy[:].T
xs, ys = interpolate(xs, ys)
self.spline.set_data(xs, ys)
self.canvas.restore_region(self.background)
self.ax.draw_artist(self.poly)
self.ax.draw_artist(self.line)
self.ax.draw_artist(self.spline)
self.canvas.blit(self.ax.bbox)
if __name__ == '__main__':
import matplotlib.pyplot as plt
from matplotlib.patches import Polygon
theta = np.arange(0, 2*np.pi, 0.1)
r = 1.5
#xs = r * np.cos(theta)
#ys = r * np.sin(theta)
xc = (921, 951, 993, 1035, 1065, 1045, 993, 945)
yc = (1181, 1230, 1243, 1230, 1181, 1130, 1130, 1130)
poly = Polygon(np.column_stack([xc, yc]), animated=True, visible = False)
fig, ax = plt.subplots()
ax.add_patch(poly)
p = PolygonInteractor(ax, poly)
ax.set_title('Click and drag a point to move it')
ax.set_xlim((800, 1300))
ax.set_ylim((1000, 1300))
plt.show()
无论如何，我认为以更少的代码行实现此结果的更好方法是使用像here 所示的路径编辑器：它避免使用多边形并且代码结果更容易。这是我的代码以获得与上面显示的相同的结果：
"""
===========
Path Editor
===========
Sharing events across GUIs.
This example demonstrates a cross-GUI application using Matplotlib event
handling to interact with and modify objects on the canvas.
"""
import numpy as np
from scipy.interpolate import interp1d
from matplotlib.backend_bases import MouseButton
from matplotlib.lines import Line2D
from matplotlib.path import Path
from matplotlib.patches import PathPatch
import matplotlib.pyplot as plt
def interpolate(x, y):
x, y = x, y
i = np.arange(len(x))
interp_i = np.linspace(0, i.max(), 100 * i.max())
xi = interp1d(i, x, kind='cubic')(interp_i)
yi = interp1d(i, y, kind='cubic')(interp_i)
return xi,yi
def dist(x, y):
"""
Return the distance between two points.
"""
d = x - y
return np.sqrt(np.dot(d, d))
def dist_point_to_segment(p, s0, s1):
"""
Get the distance of a point to a segment.
*p*, *s0*, *s1* are *xy* sequences
This algorithm from
http://geomalgorithms.com/a02-_lines.html
"""
v = s1 - s0
w = p - s0
c1 = np.dot(w, v)
if c1 <= 0:
return dist(p, s0)
c2 = np.dot(v, v)
if c2 <= c1:
return dist(p, s1)
b = c1 / c2
pb = s0 + b * v
return dist(p, pb)
class PathInteractor:
"""
An path editor.
Press 't' to toggle vertex markers on and off. When vertex markers are on,
they can be dragged with the mouse.
"""
showverts = True
epsilon = 5 # max pixel distance to count as a vertex hit
def __init__(self, spline, verts):
self.ax = spline.axes###pathpatch.axes
canvas = self.ax.figure.canvas
self.verts = verts
self.spline = spline
self.spline.set_animated(True)
x, y = zip(*self.verts)
self.line, = ax.plot(x, y, marker='o', ls = '--',
markerfacecolor='r', animated=True)
self._ind = None # the active vertex
canvas.mpl_connect('draw_event', self.on_draw)
canvas.mpl_connect('button_press_event', self.on_button_press)
canvas.mpl_connect('key_press_event', self.on_key_press)
canvas.mpl_connect('button_release_event', self.on_button_release)
canvas.mpl_connect('motion_notify_event', self.on_mouse_move)
self.canvas = canvas
def get_ind_under_point(self, event):
"""
Return the index of the point closest to the event position or *None*
if no point is within ``self.epsilon`` to the event position.
"""
# display coords
#xy = verts #np.asarray(self.pathpatch.get_path().vertices)
xyt = self.spline.get_transform().transform(self.verts)
xt, yt = xyt[:, 0], xyt[:, 1]
d = np.sqrt((xt - event.x)**2 + (yt - event.y)**2)
ind = d.argmin()
if d[ind] >= self.epsilon:
ind = None
return ind
def on_draw(self, event):
"""Callback for draws."""
self.background = self.canvas.copy_from_bbox(self.ax.bbox)
self.ax.draw_artist(self.spline)
self.ax.draw_artist(self.line)
self.canvas.blit(self.ax.bbox)
def on_button_press(self, event):
"""Callback for mouse button presses."""
if (event.inaxes is None
or event.button != MouseButton.LEFT
or not self.showverts):
return
self._ind = self.get_ind_under_point(event)
def on_button_release(self, event):
"""Callback for mouse button releases."""
if (event.button != MouseButton.LEFT
or not self.showverts):
return
self._ind = None
def on_key_press(self, event):
"""Callback for key presses."""
if not event.inaxes:
return
if event.key == 't':
self.showverts = not self.showverts
self.line.set_visible(self.showverts)
if not self.showverts:
self._ind = None
elif event.key == 'i':
xys = self.spline.get_transform().transform(verts)
p = event.x, event.y
for i in range(len(xys) - 1):
s0 = xys[i]
s1 = xys[i + 1]
d = dist_point_to_segment(p, s0, s1)
if d <= self.epsilon:
self.verts.insert(i+1, (event.xdata, event.ydata))
self.line.set_data(zip(*self.verts))
x, y = interpolate(*zip(*self.verts))
self.spline.set_data(x, y)
self.canvas.draw()
def on_mouse_move(self, event):
"""Callback for mouse movements."""
if (self._ind is None
or event.inaxes is None
or event.button != MouseButton.LEFT
or not self.showverts):
return
#vertices = verts
self.verts[self._ind] = event.xdata, event.ydata
self.line.set_data(zip(*self.verts))
x, y = interpolate(*zip(*self.verts))
self.spline.set_data(x, y)
self.canvas.restore_region(self.background)
self.ax.draw_artist(self.spline)
self.ax.draw_artist(self.line)
self.canvas.blit(self.ax.bbox)
fig, ax = plt.subplots()
verts = [
(921, 1181),
(951, 1230),
(993, 1243),
(1035, 1230),
(1065, 1181),
(1045, 1130),
(993, 1130),
(945, 1130),
(921, 1181)
]
x, y = interpolate(*zip(*verts))
spline = Line2D(x,y)
ax.add_line(spline)
interactor = PathInteractor(spline, verts)
ax.set_title('drag vertices to update path')
ax.set_xlim(800, 1300)
ax.set_ylim(1000, 1300)
plt.show()
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