The code is plotting $R_0$ against two parameters

Question

Codex 2023-10-30

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2040431-the-code-is-plotting-r_0-against-two-parameters

编辑： Dyuman Joshi 2023-11-24

在 MATLAB Online 中打开

I have been trying to run this code but it give me this error:

Error in Testing_1 (line 21)

[c,h] = contourf(alpha_3,alpha_1,R_0',levels);

%Basic Reproduction Number
alpha_m = 1/8.5; %Rate at which exposed men respectively become infectious
alpha_f = 1/22; %Rate at which exposed women respectively become infectious
tau_m = 1/8.5; %Rate at which infectious men respectively recover
tau_f = 1/21; %Rate at which infectious women respectively recover
beta_mm = 0.23; %Transmission probability from infectious men having sex with susceptible men
beta_ff = 0.18; %Transmission probability from infectious women having sex with susceptible women
beta_mf = 0.01; %Transmission probability from infectious men having sex with susceptible women
beta_fm = 0.18; %Transmission probability from infectious women having sex with susceptible men
alpha_1 = 0.01; %Modification parameters in reducing transmission
alpha_2 = 0.1; %Modification parameters in reducing transmission
alpha_3 = 1.5; %Modification parameters in reducing transmission
I_f = 27; %Population of infectious women
I_m = 28.22; %Population of infectious men
R_0 = (alpha_3 * beta_ff * tau_m + beta_mm * tau_f)/(2 * tau_f * tau_m) + sqrt(4*alpha_1*alpha_2*beta_fm*beta_mf*tau_f*tau_m + alpha_3^2*beta_ff^2*tau_m^2 - 2*alpha_3 * beta_ff * beta_mm * tau_f * tau_m + beta_mm^2 * tau_f^2)/(2 * tau_f * tau_m);
% plot
levels = (0:0.2:1.2);
[c,h] = contourf(alpha_3,alpha_1,R_0',levels);
Error using contourf
Z must be at least a 2x2 matrix.
clabel(c,h)
h.LineWidth = 2; % contour line width (up to you)
xlabel('\alpha_3');
ylabel('\alpha_1');
colormap(jet(numel(levels)-1));
colorbar('vert');

I will appreciate a response.

7 个评论
显示 5更早的评论隐藏 5更早的评论

Codex 2023-10-30

R_0 represent basic reproduction number.

alpha_1 = 0.01; %Modification parameters in reducing transmission

alpha_3 = 1.5; %Modification parameters in reducing transmission

This is to investigate the relation of the basic reproduction number (R_0) against the alpha_1 and alpha_3. And it can be R_0 against beta_mm

Dyuman Joshi 2023-11-24

编辑：Dyuman Joshi 2023-11-24

It's not possible to draw a surface plot with scalar data.

You can see that in the answer below, Walter has defined alpha_1 and alpha_3 as grids, only then a surface plot is obtained.

Are you using a research paper as reference and trying to reproduce some results? If so, then please share additional information regarding it.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Walter Roberson 2023-10-30

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/2040431-the-code-is-plotting-r_0-against-two-parameters#answer_1343661

在 MATLAB Online 中打开

I had to guess about the range of alpha_1 and alpha_3 that you wanted to plot.

The contour turns out solid color because the values of R_0 are mostly more than max(levels)

The surface is pretty boring except for a small area near the origin. And if you go too far from the origin then there is a part where the surface goes complex valued. So you would need to tell us what plot range to look at.

%Basic Reproduction Number

alpha_m = 1/8.5; %Rate at which exposed men respectively become infectious

alpha_f = 1/22; %Rate at which exposed women respectively become infectious

tau_m = 1/8.5; %Rate at which infectious men respectively recover

tau_f = 1/21; %Rate at which infectious women respectively recover

beta_mm = 0.23; %Transmission probability from infectious men having sex with susceptible men

beta_ff = 0.18; %Transmission probability from infectious women having sex with susceptible women

beta_mf = 0.01; %Transmission probability from infectious men having sex with susceptible women

beta_fm = 0.18; %Transmission probability from infectious women having sex with susceptible men

%alpha_1 = 0.01; %Modification parameters in reducing transmission

alpha_2 = 0.1; %Modification parameters in reducing transmission

%alpha_3 = 1.5; %Modification parameters in reducing transmission

I_f = 27; %Population of infectious women

I_m = 28.22; %Population of infectious men

% plot

levels = (0:0.2:1.2);

[alpha_1, alpha_3] = meshgrid(0:0.005:0.03, 1:0.05:2);

R_0 = (alpha_3 .* beta_ff .* tau_m + beta_mm .* tau_f)./(2 .* tau_f .* tau_m) + sqrt(4 .* alpha_1 .* alpha_2 .* beta_fm .* beta_mf .* tau_f .* tau_m + alpha_3.^2 .* beta_ff.^2 .* tau_m.^2 - 2 .* alpha_3 .* beta_ff .* beta_mm .* tau_f .* tau_m + beta_mm.^2 .* tau_f.^2) ./ (2 .* tau_f .* tau_m);

Name Size Bytes Class Attributes I_f 1x1 8 double I_m 1x1 8 double R_0 21x7 1176 double alpha_1 21x7 1176 double alpha_2 1x1 8 double alpha_3 21x7 1176 double alpha_f 1x1 8 double alpha_m 1x1 8 double beta_ff 1x1 8 double beta_fm 1x1 8 double beta_mf 1x1 8 double beta_mm 1x1 8 double cmdout 1x33 66 char levels 1x7 56 double tau_f 1x1 8 double tau_m 1x1 8 double

[c,h] = contourf(alpha_3,alpha_1,R_0,levels);

clabel(c,h)

h.LineWidth = 2; % contour line width (up to you)

xlabel('\alpha_3');

ylabel('\alpha_1');

colormap(jet(numel(levels)-1));

colorbar('vert');

figure()

surf(alpha_3,alpha_1,R_0);

view(3)