Q:

Matplotlib specify axes value inside an interval

I have a csv with 200 data points. If I plot it, the x-axis will take default values from 0 to 200. However, 4 data points correspond to each event, so I would like to have values from 0 to 50 on the x-axis. 
This is what I have now
import matplotlib.pyplot as plt

fig1 = plt.figure()
ax1 = fig1.add_subplot(111)

ax1.plot(val, color='blue', label='t1')
ax1.plot(val2, color='red', label='t2')
ax1.plot(val3, color='green', label='t3')
ax1.plot(val5, color='magenta', label='t4')

plt.axis([0,200,0,0.8])

plt.xlabel('Values')
plt.ylabel('Events')
ax1.legend(loc='upper right')

Any idea how I can modify this to effectively divide the numbers on the x-axis by 4 ? 

A:

Use x=np.arange(0,50,0.25) as x-value in your plots, as an example:
ax1.plot(x,val, color='blue', label='t1')

