PyQ5 Mtaplotlib Dataframe画一条随鼠标移动的竖线并标出坐标、标注

from matplotlib.widgets import MultiCursor import scipy.spatial as spatial import numpy as np def fmt(x, y): return 'x: {x:0.2f}\ny: {y:0.2f}'.format(x=x, y=y) class FollowDotCursor(object): def __init__(self, canvas, ax, df, tolerance=5, formatter=fmt, offsets=(20, 20)): self.offsets = offsets self.df = df self._points = np.column_stack((df['Time'], df['A'])) self.scale = df['Time'].ptp() self.scale = df['A'].ptp() / self.scale if self.scale else 1 self.tree = spatial.cKDTree(self.scaled(self._points)) self.formatter = formatter self.tolerance = tolerance self.ax = ax self.fig = ax.figure self.ax.xaxis.set_label_position('top') self.dot = ax.scatter( [df['Time'].min()], [df['A'].min()], s=130, color='green', alpha=0.7) self.annotation = self.setup_annotation() self.cid = self.fig.canvas.mpl_connect('motion_notify_event', self) axs = list() axs.append(ax) self.cursor = MultiCursor(canvas, axs, lw=1, ls='--') self.up_points = None def __call__(self, event): ax = self.ax inv = ax.transData.inverted() x, y = inv.transform([(event.x, event.y)]).ravel() annotation = self.annotation x, y = self.snap(x, y) annotation.xy = x, y annotation.set_text(self.formatter(x, y)) self.dot.set_offsets((x, y)) event.canvas.draw() def scaled(self, points): if len(points) == 2: time = points[0] xy = self.df[self.df["Time"] <= time] dy = self.df[self.df["Time"] > time] if xy.empty or dy.empty: return self.up_points d_min = xy['Time'].max() d_max = dy['Time'].min() pi = (d_min + d_max) / 2.0 if time <= pi: aa = self.df["A"][self.df["Time"] == d_min] points = (d_min, aa) else: aa = self.df["A"][self.df["Time"] == d_max] points = (d_max, aa) self.up_points = points return points points = np.asarray(points) return points * (self.scale, 1) def setup_annotation(self): """Draw and hide the annotation box.""" annotation = self.ax.annotate( '', xy=(0, 0), ha='right', xytext=self.offsets, textcoords='offset points', va='bottom', bbox=dict( boxstyle='round,pad=0.5', fc='yellow', alpha=0.75), arrowprops=dict( arrowstyle='->', connectionstyle='arc3,rad=0')) return annotation def snap(self, x, y): """Return the value in self.tree closest to x, y.""" dist, idx = self.tree.query(self.scaled((x, y)), k=1, p=1) try: return self._points[idx] except IndexError: # IndexError: index out of bounds return self._points[0]