plot.py

# coding=UTF-8
import sys
import matplotlib as mpl
import matplotlib.pyplot as plt
import numpy as np

mpl.rcParams['agg.path.chunksize'] = 10000

FILES = [
    './Channel4_20161004083134734.csv',
    './Channel5_20161004083153218.csv',
    './Channel6_20161004083208828.csv',
]

maxRows = 700000

if len(sys.argv) > 1:
    maxRows = int(sys.argv[1])

for filename in FILES:
    title = filename.replace('./', '').replace('.csv', '')

    # ref: <http://docs.scipy.org/doc/numpy/reference/generated/numpy.genfromtxt.html>
    data = np.genfromtxt(
        filename,
        delimiter=',',
        skip_header=0,
        skip_footer=0,
        names=['time', 'phase'],
        max_rows=maxRows
    )

    x = data['time']
    y = data['phase']

    plt.plot(x,y)

    # 設定圖的範圍, 不設的話，系統會自行決定
    rows = len(x)
    plt.xlim(0, float(rows) * 0.5555)
    plt.ylim(-4, 4)

    plt.xlabel("time")
    plt.ylabel("phase")
    plt.title(title + '(' + str(rows) + ' records)')

    # plt.show()
    plt.savefig('./plots/' + str(rows) + '_' + title + '.jpg', dpi=300, format='jpg')
    plt.clf()