Question

matlab调用函数出错，函数本身运行可以

函数本身是这样，新建脚本输入这个调用函数就会出错 [x1 x2] = equation_solve(1,2,4)出错 equation_solve (line 2)delt = b*b - 4*a*c;调用 "C:\Users\hasee\Documents\MATLAB\equation_solve.m>equation_solve" 时，未对输出参数 "x1" (可能还包括其他参数)赋值。出错 Untitled13 (line 1)[x1 x2] = equation_solve(1,2,4)求助求助
图片可能看不清，函数是很简单的，就这样
function [x1 x2] = equation_solve(a,b,c )
delt = b*b - 4*a*c;
if delt <0
'There is no answer!!!'
elseif delt == 0
'There is only one answer!'
x1 = (-b)/(2*a);
ans = x1
else
'There are two answers!'
x1 = (-b+sqrt(delt))/(2*a);
x2 = (-b-sqrt(delt))/(2*a);
ans = [x1 x2]
end

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Answer 1

因为你不知道方程有几个根，所以如果你这样调用
[x1 x2] = equation_solve(x,y,z);

则表示方程有两个根,如果求出来只有一个根或者没有那么显然x1 和 x2 不能被都赋值
你改成这样调用就可以了
equation_solve(1,2,4);

Answer 2

function [x1, x2] = equation_solve(a,b,c)
delt = b*b - 4*a*c;
if delt < 0
'There is no answer!!!'
else if delt == 0
'There is only one answer '
x1 = (-a+sqrt(delt))/2;
ans = x1
else
'There are two answers!!'
x1 = (-a+sqrt(delt))/2;
x2 = (-a-sqrt(delt))/2;
ans = [x1 x2]
end
end
原有这个文件没有问题，单独保存，相当于你自己设定了一种算法。然后你另建一个.M文件，写入代码如[x1 x2] = equation_solve(1,2,1);系统执行这行代码时将去调用上面那一段代码，然后输出结果。注意文件命名保存时要一致。

Answer 3

matlab自学一本通p132页？