Projects

Graphing in Python with Matplotlib

Matplotlib is a library for Python that allows you to create interactive graphs. You can use Matplotlib with Phidgets to visualize the data you are collecting!

Start

Setup Write Code Practice

Setup

All you need for this project is the Getting Started Kit.

Kit/ Getting Started Kit

Getting Started Kit

Install Matplotlib

In order to use Matplotlib, you first have to install it. You do this in the same way you previously installed the Phidget22 library. Simply navigate to your package manager, search for matplotlib and press install!

Thonny

If you're using Thonny, select Tools > Manage Packages and search for matplotlib.

PyCharm

If you're using PyCharm, select File > Settings > Python Interpreter and use the + symbol to install matplotlib.

PyScripter

If you're using PyScripter, select Tools > Tools > Install Packages with pip and enter matplotlib.

Write Code

Copy the code below into a new Python project. If you need a reminder of how to do this, revisit the Getting Started Course.

  
#imports for matplotlib
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation

#Add Phidgets Library 
from Phidget22.Phidget import *
from Phidget22.Devices.TemperatureSensor import *

fig, ax = plt.subplots()
size = 100 #modify this for more or less points on graph
xdata = range(0, size) #x-axis values
ydata = [0] * size #y-axis values
ln, = plt.plot(xdata, ydata, 'ro-')

#Create, open, set data interval
temperature = TemperatureSensor()
temperature.setChannel(0)
temperature.openWaitForAttachment(1000)
temperature.setDataInterval(temperature.getMinDataInterval())
    
def init():
    ax.set(xlabel='samples', ylabel='temperature (°C)',
       title='Getting Started Kit')
    ax.set_xlim(0, size)
    ax.set_ylim(10, 30) #expected range of temperature
    return ln,

def update(i, ydata):
    ydata.append(temperature.getTemperature())
    ydata = ydata[-size:]
    ln.set_ydata(ydata)    
    return ln,

ani = FuncAnimation(fig,
                    update,
                    fargs=(ydata,),
                    init_func=init,
                    interval=temperature.getDataInterval(),
                    blit=True)
plt.show()

Run your program. You will see a graph appear and it will start plotting points.

Practice

Try modifying the size variable, what does it do?
Modify the program to graph data from a different Phidget sensor like distance, or light.

Back to Projects