Matplotlib installation

Projects
1

I want to plot my analog sensor output using matplotlib but while trying to install it I am getting errors.

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2

Update your pip3 using the command

sudo -H pip3 install --upgrade pip

After that you may install matplotlib for python 3 using the command

sudo apt-get install python3-matplotlib
1 Like
3

Thank you, matplotlib installation was successful, but I could not plot using it.
from matplotlib import pyplot as plt
plt.plot(x)

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4

Could you attach the python script you are using? If there are any API keys in your code, please hide them.

5

I have only bolt API

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6

You need to convert the response which is a json object appropriately such as by using

data=json.loads(response)
if(data["success"]==1):
  actual_val=int(data["value"])

You may then use plt.plot(actual_val)

Also, please remove the second image in your previous post and reset you API keys immediately.

7

still getting errors

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8

Store the values of actual_val to a list by appending into it everytime new value is read.

list_name=[ ]
while True:
.....
  if(....):
    ....
    list_name.append(actual_val)
    plt.plot(list_name)
    plt.show()

At the end plot the list and use plt.show(list_name) to display the plot. The above method may lead to opening multiple plot windows.

9

still getting the same error

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10

Sorry, I didn’t realise you were using a server edition on your virtual machine. To view the plot you’ll require a GUI, whereas you are using a command line.
You may either use Windows or follow the below procedure to install a Desktop environment for Ubuntu.

https://phoenixnap.com/kb/how-to-install-a-gui-on-ubuntu

I’ll advise you use either Gnome 2, unity or xfce if you want to use Ubuntu.

A cleaner way would be to download the desktop version of ubuntu and install it on your virtual machine, but the above method should also work.

Note: please remove the images with API keys in your previous posts and reset the keys if you haven’t.

11

@pankajkumar.p Then, I think Raspberry Pi would be a better option. The same code can run in Raspberry Pi, right?

12

Any system that has a GUI and support for matplotlib/python should work just fine.

Operating systems for Raspberry Pi such as the official Raspbian OS also have CLI(minimal) and GUI(full) versions.

13

I tried it using raspberry pi and plot window appeared but there is no plot inside it
please help me

dd ds

14

Did you get multiple plots or just a single plot?

15

single plot window with no graph

16

Print actual_val to see if you’re getting anything on the terminal.

17

did plt.plot(actual_val) without Matplotlib installation
still got the same blank plot

18

Try something like this and check the output on the terminal

list_name=[ ]
while True:
.....
  if(....):
    ....
    list_name.append(actual_val)
    print(list_name)
    plt.plot(list_name)
    plt.show()
19

@pankajkumar.p only 1st reading is being printed and plot window appears without any graph as before
ds

20

@swethatsunil.mec,

To plot the graph there must be at-least two data points in the list . You can check this code https://repl.it/join/rkkbzovt-rahulsingh1

Since there is no display environment available thats why output will be save in graph.png file.