CODEWITHSUNDEEP
python-2.7matplotlibarduino-uno
m1sylla
m1sylla

Reputation: 91

Trying to display a title in my python graph

I'm making an oscilloscope with python and Arduino UNO. And I'm having two strange problems. First, I would like to emphasize that my code works, but I want to understand why these problems happen.

Firstly, if I try to title my figure, my code stops working. I've commented and ended with 3 question marks ??? the three lines concerned.

See code: My second question is why the buttons are not colorful (they are all black) and not clickable. See image

import serial
import numpy as np
import matplotlib.pyplot as plt
from drawnow import *


voltsent = [] #le signal reçu en chaine de caractères
signalsentfloat = [] #le signal reçu converti en float
ser = serial.Serial("com9",115200)
#affichage interactive des données
plt.ion()
cnt = 0

def figuresignal(): #fonction qui affiche le siganl analogue
    #fig = plt.figure()                                          ???
    plt.grid(True)
    #plt.legend(loc='upper left')
    plt.subplot(2,1,1)
    #fig.suptitle('Visualisation de signaux générés par le GBF')  ???
    plt.ylabel('Signal')
    plt.plot(voltsent, '.')
    plt.subplot(2,1,2)
    plt.ylabel('Fourrier Transform')
    plt.plot(voltsentFT, '-')


 while True: #while loop that loops forever
     while(ser.inWaiting()==0) :#wait here until there is a data
         pass
     signalsent = ser.readline() #read line of text from serial port
     signalsentfloat = float(signalsent) #convert it
     voltsent.append(signalsentfloat) #append its values to array
     voltsentFT = np.fft.fft(voltsent)
     drawnow(figuresignal) #call drawnow to update our the graph
     #plt.pause(.000001)
     cnt = cnt+1
     if(cnt>50):
         voltsent.pop(0)

Upvotes: 0

Views: 812

Answers (2)

m1sylla
m1sylla

Reputation: 91

I've found a solution to my problem in above question by following a tutorial on Toptechboy.com
To give a title to my graph I used the function : plt.title('Le titre ici')

Upvotes: 0

ImportanceOfBeingErnest
ImportanceOfBeingErnest

Reputation: 339230

fig = plt.figure() creates a new figure. So you would end up with a lot of figures, eventually leading the application to crash. What you want instead is to have one single figure, so put fig = plt.figure() outside the loop.

Since this would still plot a lot of lines on top of each other, the better option is to update the lines.

import serial
import numpy as np
import matplotlib.pyplot as plt

voltsent = [] #le signal reçu en chaine de caractères
signalsentfloat = [] #le signal reçu converti en float
ser = serial.Serial("com9",115200)
#affichage interactive des données
plt.ion()
cnt = 0

fig = plt.figure()
fig.suptitle(u'Visualisation de signaux générés par le GBF')

ax = plt.subplot(2,1,1)
ax.grid(True)
ax.set_ylabel('Signal')
line1, = ax.plot([],".")

ax2 = plt.subplot(2,1,2)
ax2.grid(True)
ax2.set_ylabel('Fourrier Transform')
line2, = ax2.plot([],"-")

def figuresignal(): #fonction qui affiche le siganl analogue
    line1.set_data(np.arange(len(voltsent)),voltsent )    
    line2.set_data(np.arange(len(voltsentFT)),voltsentFT )

while True: #while loop that loops forever
    while(ser.inWaiting()==0) :#wait here until there is a data
        pass
    signalsent = ser.readline() #read line of text from serial port
    signalsentfloat = float(signalsent) #convert it
    voltsent.append(signalsentfloat) #append its values to array
    voltsentFT = np.fft.fft(voltsent)
    figuresignal()
    plt.pause(.001)
    cnt = cnt+1
    if(cnt>50):
        voltsent.pop(0)

Upvotes: 1

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