CODEWITHSUNDEEP
pythonnumpymatplotlibplotannotations
TonyParker
TonyParker

Reputation: 2464

Annotating in matplotlib at each point

I am working on Radar sensor. I plot the data every time I get it from the sensor. I want to annotate each point with its characteristics e.g x.y.z. How can I do it?

I know about ax.annotate but I can do 1 point at one time. If I loop this command it slows my program. This is what I'm trying to accomplish:

radarSensor

Upvotes: 0

Views: 271

Answers (1)

TonyParker
TonyParker

Reputation: 2464

I got the answer of my own question.

We need to use .set_text() command in a loop which updates the text(characteristics of points). Here is the abstract code:

fig1=plt.figure(figsize=(15,32))
ax1=fig1.add_subplot(111, aspect='equal')
ax1.grid(True)
Ln, = ax1.plot(plot_x,plot_y,'ro') #plot_X,plot_y are lists of points
plt.ion()                          # to make figure interactive
plt.show()
......
......
......
 Ln.set_data(plot_x,plot_y)              #to updates points in the lists
 for i in range(len(plot_ann)):    #each time plot_ann number will change
     if i >= len(ann_objs):        #ann_objs is annotation object list
        ann_objs.append(ax1.annotate("", xy=(0,0)))
        ann_objs[i].set_text(plot_ann[i])
        ann_objs[i].xy = (plot_x[i], plot_y[i])
        ann_objs[i].xyann = (plot_x[i]+0.2, plot_y[i]+0.2)

Upvotes: 1

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