Connect a python tkinter progressbar to non-linear absolut values via function

Question

I am looking for a function that dynamically calculates the progresbar of a python tkinter GUI. The special thing about it is, that the values to be displayed with the percentage of the progressbar are non-linear.

• 100% should be absolut value 50
• 0% should be absolut value 2
• So the full range of the progressbar should therefore represent 48 absolut values. The problem now is, that (i.e. the half absolute value 24) should not represent the percentage value 50% but, for example, a percentage value of 74.

I get the values from an external sensor, which reads out data in real time.

How can I define this in a function that calculates the percentage values for each absolut value?

Thanks in advance!

Answer 1

This method should do the trick.

def calculate_progress(value):
    absolute_min = 2
    absolute_max = 50
    progress_min = 0
    progress_max = 100
    absolute_range = absolute_max - absolute_min
    progress_range = progress_max - progress_min
    if value <= 24:
        progress = 1.5625 * value + 3.125
    else:
        progress = 2.0833 * value - 22.0833
    progress_percentage = ((progress - absolute_min) * progress_range) / absolute_range
    return progress_percentage

Here is an example implementation.

import tkinter as tk
from tkinter import ttk

def calculate_progress(value):
    absolute_min = 2
    absolute_max = 50
    progress_min = 0
    progress_max = 100
    absolute_range = absolute_max - absolute_min
    progress_range = progress_max - progress_min
    if value <= 24:
        progress = 1.5625 * value + 3.125
    else:
        progress = 2.0833 * value - 22.0833
    progress_percentage = ((progress - absolute_min) * progress_range) / absolute_range
    return progress_percentage

def update_progress():
    global sensor_reading
    sensor_reading+=1
    progress = calculate_progress(sensor_reading)
    progress_bar['value'] = progress

sensor_reading = 0
root = tk.Tk()
root.title("Non-Linear Progress Bar Example")

progress_bar = ttk.Progressbar(root, length=400, mode='determinate', maximum=100)
progress_bar.pack(pady=20)
b = tk.Button(root,text='update', command=update_progress)
b.pack()
root.mainloop()

Hope it helps!