Octave 调用一个函数作为另一个函数的变量

Question

我在 Octave 中编写了一个二分法，但它不能使用另一个函数..

我的二分法代码是这样的:

function[x,b] = bisection(f,a,b)

  t = 10e-8

  while abs(b-a) > t;
    c = (a+b)/2;

    if f(a) * f(b) <= 0
       a = a;
       b = c;
    else 
       b = b;
       a = c
    endif
  endwhile

  x = (a+b)/2
endfunction

我已经有一个文件 f1.m:

function y = f1(x)
  y = x^2 - 4;
endfunction

但是当我调用 [x,v] = bisection[f1,0,5] 时，我得到:

>> [t,v] = bisection(f1,0,5)
   error: 'x' undefined near line 2 column 5
   error: called from
          f1 at line 2 column 3
   error: evaluating argument list element number 1

Answer 1

您想要的是将指向 f1 的指针传递给您的函数 bisection 以便正确调用

[t,v] = bisection(@f1,0,5)

哪个输出:

t =    1.0000e-07
a =  0.62500
a =  0.93750
a =  1.0938
a =  1.1719
a =  1.2109
a =  1.2305
a =  1.2402
a =  1.2451
a =  1.2476
a =  1.2488
a =  1.2494
a =  1.2497
a =  1.2498
a =  1.2499
a =  1.2500
a =  1.2500
a =  1.2500
a =  1.2500
a =  1.2500
a =  1.2500
a =  1.2500
a =  1.2500
a =  1.2500
a =  1.2500
x =  1.2500
t =  1.2500
v =  1.2500