Objective: To plot a graph(x,y) and move a vertical line over the graph w.r.t to timer.
I started implementing this using matplotlib. Its possible to implement this using draw() feature of matplotlib , but it consumes cpu as it redraws every time and doesn't allow me to interact with the graph. so i decided to use animation feature of matplotlib. in Future i would aslo like to pause the moving line. So i cant use matplotlib.animation.FuncAnimatin
Problem: I use canvas.copy_from_bbox(ax.bbox), ax.draw_artist(line),canvas.blit(ax.bbox). But, I am not able to store the graph in the background and move a line over it. When i try to store, it overwrites in a quite weird way.
This is the code i have built. Could any one please help me ? Thanks in advance.
import sys
import matplotlib.pyplot as p
import time
fig=p.figure();
ax = fig.add_subplot(1,1,1)
y=[];x=[];y1=[0,1000];x1=[0,0]
y=numpy.random.randn(1000,1)*100
x=numpy.arange(0,1000)
line1, = ax.plot(x,y,color='black');
ax.set_ylim(0, 1000);
line, = ax.plot(x1,y1,color='r',alpha=1,animated=True); # this is the line which i wanted to move over the graph w.r.t to time. ( i can also use axvline , but i guess its the same).
canvas = ax.figure.canvas
canvas.draw()
background = canvas.copy_from_bbox(ax.bbox); #my problem is here
starttime=time.time();
mytimer=0;
mytimer_ref=0;
def update(canvas,line,ax):
canvas.restore_region(background) #my problem is here
t=time.time()-starttime;
mytimer=t+mytimer_ref;
x1=[mytimer,mytimer];
line.set_xdata(x1);
ax.draw_artist(line)
canvas.blit(ax.bbox) #my problem is here
def onclick(event):
global starttime
starttime=time.time();
global mytimer_ref;
mytimer_ref=event.xdata;
print "starttime",starttime;
cid=line1.figure.canvas.mpl_connect('button_press_event',onclick); # when i click the mouse over a point, line goes to that point and start moving from there.
timer=fig.canvas.new_timer(interval=100);
args=[canvas,line,ax];
timer.add_callback(update,*args); # every 100ms it calls update function
timer.start();
p.show();