Question

Matlab 编程求助

程序如下：
function y=K(k)
%program to compute the complete eliptic integrals K(k)
%Using the arith-geom mean method
[m n]= size(k);
if m+ n= =2
K=[k k];
end
if m= =1
k= k';
end
a(:, 1)=ones(k);
b(:, 1)=sqrt(ones(k)-k.*k);
c(:, 1)=k;
i=1;
while max(c(: ,1))>eps
a(:, i+ 1)=.5*(a(a:,i)+b(:,i));
b(:, i+ 1)=sqrt(a(:,i).*b(:,i));
c(:, i+ 1)=.5*(a(:,i)-b(:,i));
i=i+1
end
t=pi*ones(k)./(2*a(:,i));
if m+n= =2
y=t(1,:);
elseif m= =1
y= t';
else
y= t;
end

运行debug后提示
??? Error: File: F:\matlab7\work\K.m Line: 5 Column: 8
The expression to the left of the equals sign is not a valid target for an assignment.
经过修改后 问题为 ??? Error: File: F:\matlab7\work\K.m Line: 16 Column: 23
Incomplete or misformed expression or statement.

Answer 1

代码巨多问题
部分问题见注释
function y=K(k)
%program to compute the complete eliptic integrals K(k)
%Using the arith-geom mean method
[m n]= size(k); % mm之间必须有，
if m+ n= =2 % 两=之间有空格
K=[k k];
end
if m= =1 % 不解释
k= k';
end
a(:, 1)=ones(k);
b(:, 1)=sqrt(ones(k)-k.*k);
c(:, 1)=k;
i=1;
while max(c(: ,1))>eps
a(:, i+ 1)=.5*(a(a:,i)+b(:,i)); %a(a:,i)这个a是什么意思
b(:, i+ 1)=sqrt(a(:,i).*b(:,i));
c(:, i+ 1)=.5*(a(:,i)-b(:,i));
i=i+1
end
t=pi*ones(k)./(2*a(:,i));
if m+n= =2
y=t(1,:);
elseif m= =1
y= t';
else
y= t;
end

追问

我就是去掉那个a 还是会提示同样的错误出来 到底是怎么回事呢

追答

调试通过版
function y=K(k)

[m n]= size(k);
if m+ n==2
K=[k k];
end
if m==1
k= k';
end
a(:, 1)=ones(k);
b(:, 1)=sqrt(ones(k)-k.*k);
c(:, 1)=k;
i=1;
while max(c(: ,1))>eps
a(:, i+ 1)=.5*(a(:,i)+b(:,i));
b(:, i+ 1)=sqrt(a(:,i).*b(:,i));
c(:, i+ 1)=.5*(a(:,i)-b(:,i));
i=i+1
end
t=pi*ones(k)./(2*a(:,i));
if m+n==2
y=t(1,:);
elseif m==1
y= t';
else
y= t;
end

追问

我直接复制你的去MATLAB7里运行 提示 Error in ==> Untitled1 at 3
[m n]= size(k)

请问师兄你用的是什么调试通过的哦

追答

加个逗号再试试
function y=K(k)

[m, n]= size(k);
if m+ n==2
K=[k k];
end
if m==1
k= k';
end
a(:, 1)=ones(k);
b(:, 1)=sqrt(ones(k)-k.*k);
c(:, 1)=k;
i=1;
while max(c(: ,1))>eps
a(:, i+ 1)=.5*(a(:,i)+b(:,i));
b(:, i+ 1)=sqrt(a(:,i).*b(:,i));
c(:, i+ 1)=.5*(a(:,i)-b(:,i));
i=i+1
end
t=pi*ones(k)./(2*a(:,i));
if m+n==2
y=t(1,:);
elseif m==1
y= t';
else
y= t;
end

追问

??? Input argument "k" is undefined.

Error in ==> Untitled1 at 3
[m,n]= size(k);

k怎么就说是没定义呢

我调用该函数 输入K（0.1） 应该是计算数值 但是提示
>> K(0.1)
??? Error using ==> ones
Size vector must be a row vector with integer elements.

Error in ==> K at 11
a(:, 1)=ones(k);

这是什么原因哦