MatPlotlib plotting live graph from sensor - python

I'm writing a GUI and part of that requires a live graph be displayed. At the moment i'm just getting a straight line being plot.
from mcculw import ul
from mcculw.enums import ULRange
from datetime import datetime as dt
from mcculw.ul import ULError
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
from matplotlib.figure import Figure
import tkinter as Tk
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation
board_num = 0
channel = 0
ai_range = ULRange.BIP5VOLTS
try:
# Get a value from the device
value = ul.a_in(board_num, channel, ai_range)
# Convert the raw value to engineering units
eng_units_value = ul.to_eng_units(board_num, ai_range, value)
# Display the raw value
print("Raw Value: " + str(value))
# Display the engineering value
print("Engineering Value: " + '{:.3f}'.format(eng_units_value))
except ULError as e:
# Display the error
print("A UL error occurred. Code: " + str(e.errorcode)
+ " Message: " + e.message)
x=[]
y=[]
fig, ax = plt.subplots()
def animate(i, x, y):
x.append(i)
y.append(eng_units_value)
ax.clear()
ax.plot(x, y)
x = x[-10:]
y = y[-10:]
ani = animation.FuncAnimation(fig, animate, fargs=(x, y), interval=100)
plt.show()
This is a snippet of the problem with the code I have.
Graph I get
No error codes - just a problem with getting a new value every time it plots i think.

Related

matplotlib animation stock one frame over the other

I have the following minimum reproducible example:
import math
import argparse
import os
import json
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation ,FFMpegWriter
line_x=[ 0,1,2,3,4,5,6,7,8,9,10,11,12 ]
line1_y=[ 3,5,7,9,11,19,23,26,29,31,37,40,45 ]
line2_y=[0,2,5,7,10,10,8,5,3,2,1,3,5]
line3_y=[39,38,32,29,26,22,19,13,10,8,7,6,3]
set_lines=[line1_y,line2_y,line3_y]
n_lineas=[1,2,3,1,3,2,3,1,3,2,1,2]
show=True #Here chabnge to False
def get_n(thelist,c):
while(c>=len(thelist)):
c-len(thelist)
return thelist[c]
class Update:
def __init__(self,ax,limit_x):
self.ax = ax
if limit_x!=0:
self.ax.set_xlim(0,limit_x)
self.ax.set_ylim(45)
self.ax.set_aspect('equal')
self.ax.grid(True)
self.lines=()
self.counter=0
def __call__(self, frame):
print("Frame: ",frame)
lines=[]
n_lines_this_time=get_n(n_lineas,self.counter)
self.counter+=1
print(n_lines_this_time,"lines this time")
for myline in range(n_lines_this_time):
#line,=self.ax.plot([],[],'.-',color=gt_color,label=legend)
line,=self.ax.plot([],[],'.-')
x = []
y = []
for v in range(13):
x.append(line_x[v])
y.append(set_lines[myline][v])
line.set_xdata(x)
line.set_ydata(y)
lines.append(line)
self.lines=tuple(lines)
return self.lines
def init(self):
print("Init")
line,=self.ax.plot([],[])
return line,
fig, ax = plt.subplots(1, 1,figsize=(10,10))
plt.gcf().canvas.mpl_connect(
'key_release_event',
lambda event: [exit(0) if event.key == 'escape' else None])
plt.xlabel("Y (meters)")
plt.ylabel("X (meters)")
ug_i = Update(ax,13)
anim = FuncAnimation(fig, ug_i,init_func=ug_i.init, frames=10, interval=1000, blit=True,repeat=False)
if not show: #This is not working. It does not erase the plots
writervideo = FFMpegWriter(fps=60)
anim.save('whatever.mp4', writer=writervideo)
print('done')
plt.close()
else:
plt.legend()
plt.show()
My problem is when show is True, I can see my animation. (it shows a different number of line each frame)
but when show is False, it seems the movie has everything all together because all the lines get shown without change.

Matplotlib animation, why no legends?

I have the following matplotlib animation. The lines get plotted with the correct color but for some reason no legend is shown when showing the plot. Notice tat plt.legend() is called. A curious thing is that the legends get shown when it is saved to a movie
import math
import argparse
import os
import json
import sys
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation ,FFMpegWriter
line_x=[ 0,1,2,3,4,5,6,7,8,9,10,11,12 ]
line1_y=[ 3,5,7,9,11,19,23,26,29,31,37,40,45 ]
line2_y=[0,2,5,7,10,10,8,5,3,2,1,3,5]
line3_y=[39,38,32,29,26,22,19,13,10,8,7,6,3]
set_lines=[line1_y,line2_y,line3_y]
n_lineas=[1,2,3,1,3,2,3,1,3,2,1,2]
show=True
thecolors=['blue','red','violet']
thelegends=['unus','duo','tres']
print(sys.argv)
if len(sys.argv)==2 and sys.argv[1]=='movie':
show=False
def get_n(thelist,c):
while(c>=len(thelist)):
c-len(thelist)
return thelist[c]
class Update:
def __init__(self,ax,limit_x):
self.ax = ax
self.lx=limit_x
if limit_x!=0:
self.ax.set_xlim(0,limit_x)
self.ax.set_ylim(0,45)
self.ax.set_aspect('equal')
self.ax.grid(True)
self.lines=()
self.counter=0
def __call__(self, frame):
print("Frame: ",frame)
lines=[]
self.ax.cla()
self.ax.set_xlim(0,self.lx)
self.ax.set_ylim(0,45)
n_lines_this_time=get_n(n_lineas,self.counter)
self.counter+=1
print(n_lines_this_time,"lines this time")
for myline in range(n_lines_this_time):
#line,=self.ax.plot([],[],'.-',color=gt_color,label=legend)
line,=self.ax.plot([],[],'.-',color=thecolors[myline],label=thelegends[myline])
x = []
y = []
for v in range(13):
x.append(line_x[v])
y.append(set_lines[myline][v])
line.set_xdata(x)
line.set_ydata(y)
lines.append(line)
plt.legend()
self.lines=tuple(lines)
return self.lines
def init(self):
print("Init")
line,=self.ax.plot([],[])
return line,
fig, ax = plt.subplots(1, 1,figsize=(10,10))
plt.gcf().canvas.mpl_connect(
'key_release_event',
lambda event: [exit(0) if event.key == 'escape' else None])
plt.xlabel("Y (meters)")
plt.ylabel("X (meters)")
ug_i = Update(ax,13)
anim = FuncAnimation(fig, ug_i,init_func=ug_i.init, frames=10, interval=1000, blit=True,repeat=False)
if not show: #This is not working. It does not erase the plots
writervideo = FFMpegWriter(fps=1)
anim.save('whatever.mp4', writer=writervideo)
print('done')
plt.close()
else:
#plt.legend()
plt.show()
Another thing I noticed is:
-In the animation there is a grid and X,Y labels but not legends but
-In the movie there is no grid and no X,Y labels but there are legends

Getting "keyerror: 0" when running my code

I am getting the below error when I try to plot a short time energy function, please I need your help solve this problem.
Code:
import os
from tqdm import tqdm
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
from scipy.io import wavfile
from python_speech_features import mfcc
from python_speech_features import logfbank
import librosa
def plot_ste(ste):
fig, axes = plt.subplots(nrows=1, ncols=1, sharex=False,
sharey=False, figsize=(400, 50))
fig.suptitle('Short Time Energy', size=100, y=1.02)
i = 0
for x in range(1):
for y in range(1):
data = list(ste.values())[i]
x, win = data[0], data[1]
axes[x,y].set_title(list(ste.keys())[i])
axes[x,y].plot(win, x)
axes[x,y].get_xaxis().set_visible(False)
axes[x,y].get_yaxis().set_visible(False)
i+=1
def ste(x, win):
"""Compute short-time energy."""
if isinstance(win, str):
win = scipy.signal.get_window(win, max(1, len(x) // 8))
win = win / len(win)
return scipy.signal.convolve(x**2, win**2, mode="same")
df = pd.read_csv('/dir/to/a.csv')
df.set_index('fname', inplace=True)
classes = list(np.unique(df.ID))
df.reset_index(inplace=True)
ste = {}
for c in classes:
wav_file = df[df.ID==c].iloc[0, 0]
signal, rate = librosa.load('/dir/to/wav_file')
ste[c] = ste
plot_ste(ste)
plt.show()
Error:
File "/home/Desktop/Program/stft_plot_full_Dir.py", line 35, in plot_ste
x, win = data[0], data[1]
KeyError: 0

Live scatter plot fetching data from firebase every 2 second

I have a mobile application which does some calculation and throws x,y coordinates and are updated on firebase every 2 seconds.
Next i want those coordinates to be plotted on a floor plan live. For that i am using Scatter plot over the floor plan image. But i cannot make it live as soon as the data is fetched need help with that.
Here is the code till now:
import matplotlib.pyplot as plt
import numpy as np
import matplotlib.animation as animation
xs = []
ys = []
fig = plt.figure()
scat = plt.scatter(xs, ys, c='r', s=100)
def main():
graph_data = open("testfile.txt","r").read()
lines = graph_data.split("\n")
for line in lines:
if len(line)>1:
x,y = line.split(",")
xs.append(x)
ys.append(y)
plt.scatter(xs,ys)
print(xs)
print(ys)
ani = animation.FuncAnimation(fig,main(),fargs=(scat))
plt.show()
Getting error with animation.FuncAnimation TypeError: NoneType object argument after * must be an iterable, not PathCollection
You can fetch data in a separate thread while updating the plot in the main one. Here is a complete working example:
#!/usr/bin/env python3
import time
from queue import Queue
from threading import Thread, Event
import numpy as np
import matplotlib.pyplot as plt
FETCH_DELAY = 2
def fetch_data(queue, stop):
while not stop.is_set():
x, y = np.random.randn(2)
queue.put((x, y))
time.sleep(FETCH_DELAY)
def limits(array, offset=1):
return array.min() - offset, array.max() + offset
def main():
stop = Event()
queue = Queue()
worker = Thread(target=fetch_data, args=(queue, stop))
worker.start()
plt.ion()
fig, ax = plt.subplots()
plot = ax.scatter([], [])
try:
while True:
data = queue.get()
data = np.array(data)
plt_data = plot.get_offsets()
plt_data = np.vstack((plt_data, data))
plot.set_offsets(plt_data)
fig.canvas.draw()
xmin, xmax = limits(plt_data[:, 0])
ymin, ymax = limits(plt_data[:, 1])
ax.set_xlim(xmin, xmax)
ax.set_ylim(ymin, ymax)
queue.task_done()
except KeyboardInterrupt:
pass
finally:
stop.set()
worker.join()
if __name__ == '__main__':
main()
Save it as plot_update.py file and run it from the command line:
python3 plot_update.py
Here is the solution without using threads it becomes very simple:
import matplotlib.pyplot as plt
import matplotlib.animation
import numpy as np
from firebase import firebase
firebase = firebase.FirebaseApplication('Firebase url', None)
fig, ax = plt.subplots()
x, y = [],[]
sc = ax.scatter(x,y,c=np.random.rand(3,))
plt.xlim(12,13)
plt.ylim(77,78)
def animate(i):
xs = firebase.get('/Lat',None)
ys = firebase.get('/Long',None)
xs = round(xs,2)
ys = round(ys,2)
file = open("testfile.txt","a+")
file.write("{0},{1} \n".format(xs,ys))
file.close()
graph_data = open("testfile.txt","r").read()
lines = graph_data.split("\n")
for line in lines:
if len(line)>1:
xs,ys = line.split(",")
x.append(xs)
y.append(ys)
sc.set_offsets(np.c_[x,y])
ani = matplotlib.animation.FuncAnimation(fig, animate,
frames=2, interval=500, repeat=True)
plt.show()

python real time plot of serial port data has huge lag

I am trying to read from serial port and plot the data in graph using matplot.
Following is my code :
I see that because of plot, there is huge lag (data in queue goes up to 10000 bytes) hence i dont see real time plot coming. Can you please help me if i am doing anything wrong.
<
import serial # import Serial Library
import numpy # Import numpy
import matplotlib.pyplot as plt
Accelerometer= []
COM_read = serial.Serial('COM5', 9600, timeout=None,parity='N',stopbits=1,rtscts=0) #Creating our serial object name
plt.ion() #Tell matplotlib you want interactive mode to plot live data
cnt=0
COM_read.flushInput()
COM_read.flushOutput()
def makeFig(): #Create a function that makes our desired plot
plt.title('My Live Streaming Sensor Data') #Plot the title
plt.grid(True) #Turn the grid on
plt.ylabel('Acc in g') #Set ylabels
plt.plot(Accelerometer, 'ro-', label='Accelerometer g') #plot the temperature
plt.legend(loc='upper left') #plot the legend
plt.ylim(15000,30000) #Set limits of second y axis- adjust to readings you are getting
print "came through"
while True: # While loop that loops forever
print COM_read.inWaiting()
while (COM_read.inWaiting()==0): #Wait here until there is data
pass #do nothing
s = COM_read.readline() #read the line of text from the serial port
decx = int(s[0:4],16)
decy = int(s[5:9],16)
decz = int(s[10:14],16)
if decx > 32768:
decx = decx - 65536;
if decy > 32768:
decy = decy - 65536;
if decz > 32768:
decz = decz - 65536;
#print decx,decy,decz
res = ((decx*decx) + (decy*decy) + (decz*decz))**(1.0/2.0)
Accelerometer.append(res) #Build our Accelerometer array by appending temp readings
drawnow(makeFig) #Call drawnow to update our live graph
plt.pause(.000001) #Pause Briefly. Important to keep drawnow from crashing
cnt=cnt+1
if(cnt>50): #If you have 50 or more points, delete the first one from the array
Accelerometer.pop(0) #This allows us to just see the last 50 data points
>
----------------Based on Dr.John's suggestion, the code is written as follows -----
import serial
import matplotlib
import threading, time
import pylab
import matplotlib.pyplot as plt
import matplotlib.animation as anim
class MAIN:
#ser =0;
def __init__(self):
self.res = 0.0
self.ser = serial.Serial('COM5', 9600, timeout=None,parity='N',stopbits=1,rtscts=0)
self.ser.flushInput()
elf.ser.flushOutput()
c = self.ser.read(1);
while(c != '\n'):
=self.ser.read(1)
return
def acquire_data(self):
s = self.ser.readline()
decx = int(s[0:4],16)
decy = int(s[5:9],16)
decz = int(s[10:14],16)
if decx > 32768:
decx = decx - 65536;
if decy > 32768:
decy = decy - 65536;
if decz > 32768:
decz = decz - 65536;
self.res = ((decx*decx) + (decy*decy) + (decz*decz))**(1.0/2.0)
print self.res
return
ex = MAIN()
threading.Timer(2,ex.acquire_data).start() #starts function acquire_data every 2 sec and resets self.res with 0.5Hz
fig, ax = plt.subplots()
ax.plot(time.time(), self.res, 'o-')
print "closed"
A while true loop is a bad idea in most cases.
Non-OO-Programming is a bad idea in most cases.
Appending plot-data to lists is a bad idea in most cases (laggy).
Start the data aquisition at defined times with
import threading, time
threading.Timer(2, acquire_data).start() #starts function acquire_data every 2 sec and resets self.res with 0.5Hz
then instead of the while-loop, please define class based functions for your own benefit:
class MAIN:
def __init__(self):
self.res = 0
def acquire_data(self):
....
return self.res
and plot with
fig, ax = plt.subplots()
ax.plot(time.time(), self.res, 'o-')
Greets Dr. Cobra

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