MATLAB：如何將參數傳遞給函數？

Question

我有以下功能：

function ypdiff = ypdiff(t,y) 
    a = 0.01; 
    b = 0.1; 
    ypdiff(1) = -a*y(1)*y(2); 
    ypdiff(2) = b*y(1)*y(2)-b*y(2); 
    ypdiff(3) = b*y(2); 
    ypdiff = [ypdiff(1) ypdiff(2) ypdiff(3)]'; 

如果我想解決這個問題，我會打電話的ODE45功能如下：

[t y] = ode45(@ypdiff, [to tf], yo); 

但是，如果我想要一個參數傳遞給這個函數，我將如何使用ode45功能？具體來說，我想以下配方：

function ypdiff = ypdiff(t,y,u) 
    a = 0.01; 
    b = 0.1; 
    ypdiff(1) = -a*u*y(1)*y(2); 
    ypdiff(2) = b*u*y(1)*y(2)-b*y(2); 
    ypdiff(3) = b*u*y(2); 
    ypdiff = [ypdiff(1) ypdiff(2) ypdiff(3)]'; 

Answer 1

您可以使用MATLAB中的anonymous function（類似於其他語言的lambda函數）：

u = 1.2; 
[t y] = ode45(@(t, y) ypdiff(t, y, u), [to tf], yo);