y-axis not showing correct values in matplotlib.animation

Question

This code constructs a matplotlib figure, gets data using the get_data function from a webpage in the open, high, low, close format and appends these values to a list every five minutes using FuncAnimation which then updates a candlestick chart. However, the y axis values are not correct as they display only 1-7 and should be current S&P prices of around 2500. How to fix?

import matplotlib.pyplot as plt
from matplotlib.finance import candlestick2_ohlc
import matplotlib.animation as animation
from matplotlib import style
from es_cme_quote import get_data
import numpy as np

style.use('ggplot')
fig=plt.figure()
ax= fig.add_subplot(111)
o_array=[]
h_array=[]
l_array=[]
c_array=[]
def update(dummy):

    [O,H,L,C]=get_data()

    def append_var(x,y):
        y.append(x)

    append_var(O[0],o_array)
    append_var(H[0],h_array)
    append_var(L[0],l_array)
    append_var(C[0],c_array)
    ax.clear()
    candlestick2_ohlc(ax,o_array,h_array,l_array,c_array,
    width=.8,colorup='g',colordown='r',alpha=1.0)

anime=animation.FuncAnimation(fig,update,interval=300000)
plt.show()

Mohsin · Answer 1 · 2017-09-26T14:22:18.777

1

For a single plot within a figure.

axes = plt.gca()
axes.set_ylim([ymin,ymax])

Source: setting y-axis limit in matplotlib

edited Sep 26 '17 at 14:22

answered Sep 26 '17 at 14:01

Mohsin

536
6
18

tried ax.set_ylim([np.min(l_array),np.max(h_array)]) and ax=plt.gca() within the update function and all manners of adding it still doesn't work. – Andre Wallin Sep 26 '17 at 14:23
The solution is like you said but no set_ylim just ax=plt.cla() placed above ax.clear() – Andre Wallin Sep 26 '17 at 14:35
Thank you for the solution to my problem – Andre Wallin Sep 26 '17 at 14:59

score 1 · Answer 2 · answered Sep 26 '17 at 14:37

import matplotlib.pyplot as plt
from matplotlib.finance import candlestick2_ohlc
import matplotlib.animation as animation
from matplotlib import style
from es_cme_quote import get_data
import numpy as np

style.use('ggplot')
fig=plt.figure()
ax= fig.add_subplot(111)
o_array=[]
h_array=[]
l_array=[]
c_array=[]
def update(dummy):

    [O,H,L,C]= get_data()

    def append_var(x,y):
        y.append(x)
    append_var(O[0],o_array)
    append_var(H[0],h_array)
    append_var(L[0],l_array)
    append_var(C[0],c_array)

    ax=plt.gca()
    ax.clear()
    candlestick2_ohlc(ax,o_array,h_array,l_array,c_array,
    width=.8,colorup='g',colordown='r',alpha=1.0)

anime=animation.FuncAnimation(fig,update,interval=300000)
plt.show()

y-axis not showing correct values in matplotlib.animation

2 Answers2