将X绘制在X上，因为X是y的每个值的时间范围

Question

I'm trying to plot a simple graph to no avail!

Instead of this the best i can come up with is this one

Even this simple one isn't working, the main problem is I need the line to go just horizontal say for 5 mins at a constant y value then the value changes and I want it to go constant for another 10 mins or so. Something like this:

Y = [5, 10, 11, 6]

X = [0-10mins, 10mins-25mins, 25-45mins, 45-50mins]

plot Y on against X

Answer 1

I think you need a step function. Please note that here I added 0 to X and 5 to Y in the beginning so as to have the correct first step span from 0 to 10

import matplotlib.pyplot as plt

X = [0, 10, 25, 45, 50]
Y = [5, 5, 10, 11, 6]

plt.step(X, Y)
plt.show()

EDIT: If you have unsorted X-array and you want to sum up the X values, you can use cumsum from NumPy. The main idea here is to first insert 0 to your list and then convert to array followed by cumulative summing

import matplotlib.pyplot as plt
import numpy as np

X = [6, 27, 9, 19]
X.insert(0,0)
X = np.cumsum(X)

Y = [5, 5, 10, 11, 6]

plt.step(X, Y)
plt.show()

Answer 2

I propose a simple loop solution like below. In order to make the figure nicer, you can specify different colors, texts and so on.

#!/usr/bin/env ipython
# ------------------
import numpy as np
import matplotlib as mpl
import matplotlib.pylab as plt
# --------------------
xdata=[0,10,25,45,50]
ydata=[5,10,11,6];
colors=['b','b','b','b']
# --------------------
fig=plt.figure();
ax=fig.add_subplot(111);
for i in range(len(xdata)-1):
    xloc=0.5*(xdata[i+1]+xdata[i])
    xwidth=xdata[i+1]-xdata[i];
    ax.bar(xloc,ydata[i],width=xwidth,color=colors[i]);
plt.show()