Question

我是Python的新手，我正在尝试从不断增长的CSV中提取数据，并创建实时更新图。我想创建两个不同的x，y数组，具体取决于数据通过哪个天线（用逗号分隔的每行数据中的一个值）。数据文件如下所示：

＆＃13;

TimeStamp, ReadCount, Antenna, Protocol, RSSI, EPC, Sensor
09/21/2016 15:24:40.560, 5499, 1, GEN2, -21, E036112D912508B3, 23.78,47.00,0.00,2.21, (Infinity%)
09/21/2016 15:24:41.138, 5506, 1, GEN2, -9, E036112D912508B3, 23.99,46.00,0.00,2.26, (Infinity%)
09/21/2016 15:24:41.623, 5513, 1, GEN2, -25, E036112D912508B3, 23.99,46.00,0.00,2.26, (Infinity%)
09/21/2016 15:24:42.120, 5520, 1, GEN2, -18, E036112D912508B3, 23.78,46.00,0.00,2.26, (Infinity%)
09/21/2016 15:24:42.633, 5527, 1, GEN2, -12, E036112D912508B3, 23.99,45.00,0.00,2.23, (Infinity%)
09/21/2016 15:24:43.211, 5534, 1, GEN2, -9, E036112D912508B3, 23.99,46.00,0.00,2.26, (Infinity%)
09/21/2016 15:24:43.744, 5541, 1, GEN2, -16, E036112D912508B3, 23.99,46.00,0.00,2.26, (Infinity%)

＆＃13;

我已成功显示图表的代码，但只是将所有数据行接收到一个x，y数组中，如下所示：

＆＃13;

import matplotlib
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from datetime import datetime
      
offset = -7.4954
slope = 0.9548

fig = plt.figure(facecolor='#07000d')

ax1 = fig.add_subplot(111, axisbg='#07000d')

ax1.spines['bottom'].set_color("#5998ff")
ax1.spines['top'].set_color("#5998ff")
ax1.spines['left'].set_color("#5998ff")
ax1.spines['right'].set_color("#5998ff")
    
def animate(i):
    graph_data = open('SensorLog.csv','r').read()
    dataArray = graph_data.split('\n')

    xar=[]
    yar=[]
    
    for eachLine in dataArray:
        if 'TimeStamp' not in eachLine: 
            if len(eachLine)>1:
                t,rc,ant,prot,rssi,epc,temp,ten,powr,unpowr,inf=(eachLine.split(','))         
                time = datetime.strptime(t, '%m/%d/%Y %H:%M:%S.%f')
                clock = time.strftime('%I:%M')
                xs = matplotlib.dates.datestr2num(clock)
                hfmt = matplotlib.dates.DateFormatter('%m/%d/%Y\n%I:%M:%S %p')

#                Convert tension
                tension = int(float(ten)*float(slope)+float(offset))
                
                xar.append(xs)
                yar.append(tension)
                
    ax1.clear()
    
    ax1.grid(True, color='w')

    plt.ylabel('Tension (lb)',color='w', fontsize=20)
    plt.title('Spiral 1 Tension',color='w', fontsize=26)

       
    ax1.tick_params(axis='y', colors='w')
    ax1.tick_params(axis='x', colors='w')
    ax1.xaxis.set_major_formatter(hfmt)

    fig.autofmt_xdate()
    
    ax1.plot (xar,yar, 'c', linewidth=2)

ani = animation.FuncAnimation(fig, animate, interval=10000)
plt.show()

＆＃13;

我正在尝试将天线1和2上的数据分开，并使用不同的彩色线图在同一图表（共享x轴）上绘制每个数据...我的尝试在这里，但它不起作用：

＆＃13;

import matplotlib
import matplotlib.pyplot as plt
import matplotlib.animation as animation
from datetime import datetime
      
offset = -7.4954
slope = 0.9548

fig = plt.figure(facecolor='#07000d')

ax1 = fig.add_subplot(111, axisbg='#07000d')
ax2 = fig.add_subplot(111, axisbg='#07000d')

ax1.spines['bottom'].set_color("#5998ff")
ax1.spines['top'].set_color("#5998ff")
ax1.spines['left'].set_color("#5998ff")
ax1.spines['right'].set_color("#5998ff")

ax2.spines['bottom'].set_color("#5998ff")
ax2.spines['top'].set_color("#5998ff")
ax2.spines['left'].set_color("#5998ff")
ax2.spines['right'].set_color("#5998ff")
    
def animate(i):
    graph_data = open('SensorLog.csv','r').read()
    dataArray = graph_data.split('\n')

    xar=[]
    yar=[]
    xar2=[]
    yar2=[]    

    for eachLine in dataArray:
        if 'TimeStamp' not in eachLine: 
            if len(eachLine)>1:
                t,rc,ant,prot,rssi,epc,temp,ten,powr,unpowr,inf=(eachLine.split(','))         
                time = datetime.strptime(t, '%m/%d/%Y %H:%M:%S.%f')
                clock = time.strftime('%I:%M')
                xs = matplotlib.dates.datestr2num(clock)
                hfmt = matplotlib.dates.DateFormatter('%m/%d/%Y\n%I:%M:%S %p')

#                Convert tension
                tension = int(float(ten)*float(slope)+float(offset))
                              
                if ant == '1':
                    xar.append(xs)
                    yar.append(tension)
               
                if ant == '2':
                    xar2.append(xs)                    
                    yar2.append(tension)
                   
    ax1.clear()
    ax2.clear()
    
    ax1.grid(True, color='w')
    ax2.grid(True, color='w')

    plt.ylabel('Tension (lb)',color='w', fontsize=20)
    plt.title('Spiral 1 Tension',color='w', fontsize=26)

       
    ax1.tick_params(axis='y', colors='w')
    ax1.tick_params(axis='x', colors='w')
    ax1.xaxis.set_major_formatter(hfmt)
   
    ax2.tick_params(axis='y', colors='w')
    ax2.tick_params(axis='x', colors='w')
    ax2.xaxis.set_major_formatter(hfmt)
   
    fig.autofmt_xdate()
    
    ax1.plot (xar,yar, 'c', linewidth=2)
    ax2.plot (xar2,yar2,'r', linewidth=3)

ani = animation.FuncAnimation(fig, animate, interval=10000)
plt.show()

＆＃13;

你们有没有关于如何成功分离ant 1和ant 2数据以及在不同颜色的同一图上绘制它的信息？

Answer 1

您可以使用相同的轴简单地绘制每个数据集。

以下方法使用Python csv.DictReader来帮助读取数据，并使用defaultdict(list)自动将数据拆分为基于每行天线的列表。

这也添加了代码来解决您的评论，这些评论将数据点分组的时间间隔不超过60秒，并且只显示最后5分钟的条目：

import matplotlib
import matplotlib.pyplot as plt
import matplotlib.animation as animation

from datetime import datetime, timedelta
import collections
import csv

offset = -7.4954
slope = 0.9548

def plot(ax, data, colour, width):
    if data:
        last_dt = data[0][0]
        sixty = timedelta(seconds=60)

        x = []
        y = []

        # Plot groups of data not more than 60 seconds apart
        for dt, ten in data:
            if dt <= last_dt + sixty:
                x.append(dt)
                y.append(ten)
            else:
                ax.plot(matplotlib.dates.date2num(x), y, colour, linewidth=width)
                x = [dt]
                y = [ten]

            last_dt = dt

        ax.plot(matplotlib.dates.date2num(x), y, colour, linewidth=width)


def animate(i, fig, ax):
    # Read in the CSV file
    data = collections.defaultdict(list)
    fields = ["TimeStamp", "ReadCount", "Antenna", "Protocol", "RSSI", "EPC", "Temp", "Ten", "Powr", "Unpowr", "Inf"]

    with open('SensorLog.csv') as f_input:
        csv_input = csv.DictReader(f_input, skipinitialspace=True, fieldnames=fields)
        header = next(csv_input)

        # Separate the rows based on the Antenna field
        for row in csv_input:
            try:
                data[row['Antenna']].append(
                    [datetime.strptime(row['TimeStamp'], '%m/%d/%Y %H:%M:%S.%f'), 
                    int(float(row['Ten']) * float(slope) + float(offset))])
            except TypeError as e:
                pass

    # Drop any data points more than 5 mins older than the last entry

    latest_dt = data[row['Antenna']][-1][0]     # Last entry
    not_before = latest_dt - timedelta(minutes=5)

    for antenna, entries in data.items():
        data[antenna] = [[dt, count] for dt, count in entries if dt >= not_before]

    # Redraw existing axis
    ax.clear()

    ax.spines['bottom'].set_color("#5998ff")
    ax.spines['top'].set_color("#5998ff")
    ax.spines['left'].set_color("#5998ff")
    ax.spines['right'].set_color("#5998ff")

    hfmt = matplotlib.dates.DateFormatter('%m/%d/%Y\n%I:%M:%S %p')
    ax.xaxis.set_major_formatter(hfmt)
    fig.autofmt_xdate()

    plot(ax, data['1'], 'c', 2)     # Antenna 1
    plot(ax, data['2'], 'r', 3)     # Antenna 2

    ax.grid(True, color='w')
    plt.ylabel('Tension (lb)', color='w', fontsize=20)
    plt.title('Spiral 1 Tension', color='w', fontsize=26)

    ax.tick_params(axis='y', colors='w')
    ax.tick_params(axis='x', colors='w')

fig = plt.figure(facecolor='#07000d')
ax = fig.add_subplot(111, axisbg='#07000d')

ani = animation.FuncAnimation(fig, animate, fargs=(fig, ax), interval=1000)
plt.show()

这会给你以下类型的输出：

如何通过每行中的值分隔和绘制数组中的行

1 个答案: