#-*- coding: utf-8 -*-
#---------------------------------------------------
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.ticker import MultipleLocator, FormatStrFormatter
import csv
#---------------------------------------------------
def data_process():
    # excelfile = xlrd.open_workbook(r'C:\Users\laich\Desktop\harda.xlsx')
    excelfile = csv.reader(open(r'C:\Users\laich\Desktop\scope_data.csv'))
    data = []
    for stu in excelfile:
        data.append(stu)

    dates = get_date(0,data)
    ia = get_num(1,data)
    ib = get_num(2,data)
    ic = get_num(3,data)
    ua = get_num(4,data)
    ub = get_num(5,data)
    uc = get_num(6,data)
    ax = plt.subplot(111) #注意:一般都在ax中設定,不再plot中設定
    # plt.plot(dates,ia,'r')
    # plt.plot(dates,ib,'y')
    # plt.plot(dates,ic,'b')
    plt.plot(ia,'r')
    plt.plot(ib,'y')
    plt.plot(ic,'b')
    #設定主刻度標籤的位置,標籤文字的格式
    xmajorLocator   = MultipleLocator(2500) #將x主刻度標籤設定為n的倍數
    xmajorFormatter = FormatStrFormatter('%1.1f') #設定x軸標籤文字的格式
    ax.xaxis.set_major_locator(xmajorLocator)
    ax.xaxis.set_major_formatter(xmajorFormatter)
    # plt.xticks([0,4999,9999,14999,19999],[dates[0],dates[4999],dates[9999],dates[14999],dates[19999]])
    plt.xticks([0,2499,4999,7499,9999,12499,14999,17499,19999],[dates[0],dates[2499],dates[4999],dates[7499],dates[9999],dates[12499],dates[14999],dates[19999]])
    plt.legend(['ia','ib','ic'])
    plt.xticks(rotation=15)
    plt.show()

def get_date(ids,data):
    getnum = []
    row,col = np.shape(data)
    for i in range(1,row):
        getnum.append(data[i][ids])
    return getnum

def get_num(ids,data):
    getnum = []
    row,col = np.shape(data)
    for i in range(1,row):
        getnum.append(float(data[i][ids]))
    return getnum

if __name__ == '__main__':
    data_process()
 

主要函式在於

#設定主刻度標籤的位置,標籤文字的格式
xmajorLocator   = MultipleLocator(2500) #將x主刻度標籤設定為n的倍數
xmajorFormatter = FormatStrFormatter('%1.1f') #設定x軸標籤文字的格式
ax.xaxis.set_major_locator(xmajorLocator)
ax.xaxis.set_major_formatter(xmajorFormatter)

這裡MultipleLocator用於設定間隔多少個刻度顯示一個刻度值

plt.xticks([0,2499,4999,7499,9999,12499,14999,17499,19999],[dates[0],dates[2499],dates[4999],dates[7499],dates[9999],dates[12499],dates[14999],dates[19999]])

函式xticks用於將數值刻度轉換成任意字元刻度

plt.xticks(rotation=15)

將顯示的刻度旋狀防止重疊

顯示效果如下