GUI simulation of the new coronavirus (SEIR model)

Introduction

In the previous article, I posted a program that predicts the behavior of the new coronavirus in the SEIR model. This time, we have made the program into a GUI, so we will share the contents.

`Previous article: I tried to predict the behavior of the new coronavirus with the SEIR model. `` Link: https://qiita.com/kotai2003/items/ed28fb723a335a873061

Execution screen

List of input parameters

Currently, many research papers have been published to estimate SEIR parameters from the cases of new coronavirus cases. This time, I will calculate the SEIR model with the parameter estimates published in the paper published on February 16. (Reference 2)

Execution example

For example, [Social Distance Strategy](https://ja.wikipedia.org/wiki/%E7%A4%BE%E4%BC%9A%E8%B7%9D%E9%9B%A2%E6%88%A6 With% E7% 95% A5), it is possible to simulate how the peak of infected people fluctuates when the infection rate drops from 0.5 to 0.4.

Case 1: Infection rate 0.5

Source code

main_routine.py

import tkinter as tk
from tkinter import ttk
from tkinter import Menu
from tkinter import messagebox

import numpy as np
from scipy.integrate import odeint
import matplotlib.pyplot as plt
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg

from calcSEIR import SEIR_EQ

class Application(tk.Frame):
    def __init__(self,master):
        super().__init__(master)
        self.pack()

        self.master.geometry("1000x600")
        self.master.title("SEIR Epidemic Model Simulator")

        self.create_widgets()

    def create_widgets(self):
        #Canvas Frame

        self.canvas_frame = tk.Frame(self)
        self.canvas_frame.configure(width=600, height=480)
        self.canvas_frame.grid(row=0, column=0)
        self.canvas_frame.grid(padx = 20, pady=20)


        #Label Frame for Input Parameters
        self.frame_param = tk.LabelFrame( self )
        self.frame_param.configure( text=' Input Paramaters ' )
        self.frame_param.grid( row=0, column=1 )
        self.frame_param.grid( padx=20, pady=20 )

        #1. Population
        #Label_population
        self.label_popu = tk.Label( self.frame_param)
        self.label_popu.configure(text ='Population (Million)')
        self.label_popu.grid(row =0, column = 0)
        #Scale population
        self.var_popu = tk.DoubleVar() #scale variable
        self.scale_popu = tk.Scale( self.frame_param)
        self.scale_popu.configure(orient="horizontal")
        self.scale_popu.configure(from_=1, to= 1350)
        self.scale_popu.configure(variable=self.var_popu)
        self.scale_popu.grid(row=0, column=1)

        #2. Infection Rate
        # Label_Infection_Rate
        self.label_IR = tk.Label( self.frame_param )
        self.label_IR.configure( text='Infection Rate' )
        self.label_IR.grid( row=1, column=0 )
        # Scale Infection_Rate
        self.var_IR = tk.DoubleVar()  # scale variable
        self.scale_IR = tk.Scale( self.frame_param )
        self.scale_IR.configure( orient="horizontal" )
        self.scale_IR.configure( from_=0.1, to=2 , resolution=0.1)
        self.scale_IR.configure( variable=self.var_IR )
        self.scale_IR.grid( row=1, column=1 )

        #3. Latency Period
        # Label_
        self.label_LP = tk.Label( self.frame_param )
        self.label_LP.configure( text='Latency Period (days)' )
        self.label_LP.grid( row=2, column=0 )
        # Scale
        self.var_LP = tk.IntVar()  # scale variable
        self.scale_LP = tk.Scale( self.frame_param )
        self.scale_LP.configure( orient="horizontal" )
        self.scale_LP.configure( from_=1, to=14 , resolution=0.1)
        self.scale_LP.configure( variable=self.var_LP )
        self.scale_LP.grid( row=2, column=1 )

        # 3.5 Infection Period
        # Label_
        self.label_IP = tk.Label( self.frame_param )
        self.label_IP.configure( text='Infections Period (days)' )
        self.label_IP.grid( row=3, column=0 )
        # Scale
        self.var_IP = tk.IntVar()  # scale variable
        self.scale_IP = tk.Scale( self.frame_param )
        self.scale_IP.configure( orient="horizontal" )
        self.scale_IP.configure( from_=1, to=14, resolution=0.1 )
        self.scale_IP.configure( variable=self.var_IP )
        self.scale_IP.grid( row=3, column=1 )

        #4 E_0
        self.label_E0 = tk.Label( self.frame_param )
        self.label_E0.configure( text='E(t=0)' )
        self.label_E0.grid( row=4, column=0 )
        #Entry
        self.Entry_E0 = tk.Entry(self.frame_param)
        self.Entry_E0.grid(row=4, column=1)
        self.Entry_E0.insert(tk.END,"696")

        #5 I_0
        self.label_I0 = tk.Label( self.frame_param )
        self.label_I0.configure( text='I(t=0)' )
        self.label_I0.grid( row=5, column=0 )
        # Entry
        self.Entry_I0 = tk.Entry( self.frame_param )
        self.Entry_I0.grid( row=5, column=1 )
        self.Entry_I0.insert( tk.END, "652" )

        #6 R_0
        self.label_R0 = tk.Label( self.frame_param )
        self.label_R0.configure( text='E(t=0)' )
        self.label_R0.grid( row=6, column=0 )

        # Entry
        self.Entry_R0 = tk.Entry( self.frame_param )
        self.Entry_R0.grid( row=6, column=1 )
        self.Entry_R0.insert( tk.END, "0" )

        #7 Time
        self.label_time = tk.Label(self.frame_param)
        self.label_time.configure( text = 'Time [days]')
        self.label_time.grid(row=7, column=0)

        self.var_time = tk.IntVar()  # scale variable
        self.scale_time = tk.Scale( self.frame_param )
        self.scale_time.configure( orient="horizontal" )
        self.scale_time.configure( from_=10, to=500, resolution=1 )
        self.scale_time.configure( variable=self.var_time )
        self.scale_time.grid( row=7, column=1 )

        #Basic Reproduction Number

        # Label Frame result
        self.frame_basicR0 = tk.LabelFrame( self )
        self.frame_basicR0.configure( text=' Basic Reproduction Number ' )
        self.frame_basicR0.grid( row=2, column=1 )
        self.frame_basicR0.grid( padx=20, pady=20 )

        self.label_basicR0 = tk.Label(self.frame_basicR0)
        self.label_basicR0.grid(row = 0, column=0)
        self.label_basicR0.configure(text = '  R0 is ')

        self.msg_basicR0 = tk.Message(self.frame_basicR0)
        self.msg_basicR0.grid(row=0, column=1)
        self.msg_basicR0.configure(text ='')


        # Button

        ##Label Frame for Buttons

        # Label Frame for Input Parameters
        self.frame_button = tk.LabelFrame( self )
        self.frame_button.configure( text=' Operation ' )
        self.frame_button.grid( row=2, column=0 )
        self.frame_param.grid( padx=20, pady=20 )

        #button
        # Plot (Rungekutta. Plot..Canvas..)
        self.button_plot = tk.Button( self.frame_button )
        self.button_plot.configure( text='Calculate & Plot' )
        self.button_plot.grid( column=0, row=1 )
        self.button_plot.configure( command=self.plotCalc )
        self.button_plot.configure(width = 20, height=2)

        # Quit Button
        self.button_quit = tk.Button( self.frame_button )
        self.button_quit.config( text='Quit' )
        self.button_quit.grid( column=2, row=1 )
        self.button_quit.configure( command=self.quit_app )
        self.button_quit.configure( width = 15, height=2 )

## Event Call Back

    def plotCalc(self):

        # parameters
        self.t_max = self.var_time.get()  # days
        self.dt = 0.01
        # initial_state

        self.N_pop = 1e6*self.var_popu.get()
        self.E_0 = int(self.Entry_E0.get())
        self.I_0 = int(self.Entry_I0.get())
        self.R_0 = int(self.Entry_R0.get())
        self.S_0 = self.N_pop - (self.E_0 + self.I_0 + self.R_0)
        self.ini_state = [self.S_0, self.E_0, self.I_0, self.R_0]  # [S[0],E,[0], I[0], R[0]]

        #Infection rate
        self.beta_const = self.var_IR.get()  #Infection rate
        #Rate of getting infection after exposure
        self.epsilon_const = 1 / self.var_LP.get()
        #Recovery rate and quarantine rate
        self.gamma_const = 1 / self.var_IP.get()

        #Basic Reproduction number in SEIR model
        self.basicR0 = self.beta_const/self.gamma_const +self.beta_const/self.epsilon_const
        self.msg_basicR0.configure( text=str(self.basicR0) )

        #https://www.fields.utoronto.ca/programs/scientific/10-11/drugresistance/emergence/fred1.pdf


        # numerical integration
        self.times = np.arange( 0, self.t_max, self.dt )
        self.args = (self.beta_const, self.epsilon_const, self.gamma_const, self.N_pop)

        # Numerical Solution using scipy.integrate
        # Solver SEIR model
        self.result = odeint(SEIR_EQ, self.ini_state, self.times, self.args )

        ## Plotting

        # Generate Figure instance
        self.fig = plt.Figure()

        #Generate Axe instance
        #ax1
        self.ax1 = self.fig.add_subplot(111)
        self.ax1.plot(self.times, self.result)
        self.ax1.set_title('SEIR Epidemic model')
        self.ax1.set_xlabel('time [days]')
        self.ax1.set_ylabel('population [persons]')
        self.ax1.legend(['Susceptible', 'Exposed', 'Infectious', 'Removed'])
        self.ax1.grid()

        #Link to Axe instance to Canvas
        #Then show Canvas onto canvas_Frame
        self.canvas = FigureCanvasTkAgg( self.fig, self.canvas_frame )
        self.canvas.draw()
        self.canvas.get_tk_widget().grid(column=0, row=0)



    def quit_app(self):
        self.Msgbox = tk.messagebox.askquestion( "Exit Applictaion", "Are you sure?", icon="warning" )
        if self.Msgbox == "yes":
            self.master.destroy()
        else:
            tk.messagebox.showinfo( "Return", "you will now return to application screen" )




def main():
    root = tk.Tk()
    app = Application(master=root)#Inherit
    app.mainloop()

if __name__ == "__main__":
    main()

calcSEIR.py

# Define differential equation of SEIR model

'''
dS/dt = -beta * S * I / N
dE/dt = beta* S * I / N - epsilon * E
dI/dt = epsilon * E - gamma * I
dR/dt = gamma * I

[v[0], v[1], v[2], v[3]]=[S, E, I, R]

dv[0]/dt = -beta * v[0] * v[2] / N
dv[1]/dt = beta * v[0] * v[2] / N - epsilon * v[1]
dv[2]/dt = epsilon * v[1] - gamma * v[2]
dv[3]/dt = gamma * v[2]

'''

def SEIR_EQ(v, t, beta, epsilon, gamma, N ):
    return [-beta * v[0] * v[2] / N ,beta * v[0] * v[2] / N - epsilon * v[1],
            epsilon * v[1] - gamma * v[2],gamma * v[2]]

Reference material

1. I tried to predict the behavior of the new coronavirus with the SEIR model.
2. Epidemic analysis of COVID-19 in China by dynamical modeling
3. [Python] Tkinter template
4. Embed matplotlib graph in Tkinter
5. Introduction of Mathematical Prediction Model for Infectious Diseases (SIR Model)
6. Response to new coronavirus infection