Programme not running when using fsolver.

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Honey Adams 2018-8-6

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/413685-programme-not-running-when-using-fsolver

评论： Honey Adams 2018-8-8

采纳的回答： Walter Roberson

I would be glad if anyone could help me identify the reason my code isn't running when using fsolve.

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Honey Adams 2018-8-7

I posted it there since the conversation here got stuck.

Honey Adams 2018-8-7

Doy you mind helping me out ?Thank you

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采纳的回答

Walter Roberson 2018-8-6

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https://ww2.mathworks.cn/matlabcentral/answers/413685-programme-not-running-when-using-fsolver#answer_331705

在 MATLAB Online 中打开

Your V and Z is 10 x 6 and your r and s is 6 x 1 and your k is 10 x 1. These all go together in a way such that for

     f(1)=(1/(1+b^2 +g^2)*((V'*V)^-1 * V'*((center-(W*r + Z*s))+ (left-(W*r +Z*s)*...
       b - k*d)*b + (right-(W*r+Z*s)*g - k*h)*g)))-a;

the right hand side is 6 x 1. A 6 x 1 vector cannot be stored in a single numeric location such as f(1)

The f(2) and f(3) entries have the same size difficulty.

You have

          f(4)=  ((a'*V' + r' * W' + s'*Z')*(V*a + W*r + Z*s)^-1 *(left'*(V*a +W*r + Z*s)...
          -(a'*V' + r'*W' +s'*Z')*k*d))- b;

The ^-1 has priority over matrix multiplication, so the (V*a + W*r + Z*s) is computed and attempted to be raised to -1. But (V*a + W*r + Z*s) is 10 x 1 and you can only raise a non-scalar with ^-1 if you are working with a square matrix.

f(5) has the same problems as f(4).

f(6) and f(7) are okay: they each compute scalars.

Your ^-1 of matrices are matrix inverse requests, just as if you had coded inv() . However, you should avoid coding ^-1 or inv() calls as that operation is not numerically stable. You should be changing to using the / or \ operators. For example,

(V'*V)^-1 * V'*ETC

should be re-coded as

(V'*V) \ V'

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Honey Adams 2018-8-6

编辑：Walter Roberson 2018-8-7

在 MATLAB Online 中打开

Hello Walter, please I tried working on it but I will need your help as it still isn't running.

function f = FIFON(x,V,W,Z,k,center,left,right)
a=[x(1);x(2);x(3);x(4);x(5);x(6)];
r=[x(7);x(8);x(9);x(10);x(11);x(12)];
s=[x(13);x(14);x(15);x(16);x(17);x(18)];
b=x(19);
g=x(20);
d=x(21);
h=x(22);
       f=[(1/(1+b^2 + g^2))*(((V'*V)\ V')*((center- W*r + Z*s)+ (left-(W*r +Z*s)*b...
       - k*d)*b + (right-(W*r + Z*s)*g - k*h)*g)) -a;
          (1/(1+b^2 +g^2))*(((W'*W)\ W')*((center- V*a + Z*s)+ (left-(V*a +Z*s)*...
           b - k*d)*b + (right-(V*a + Z*s)*g - k*h)*g))-r;
         (1/(1+b^2 +g^2))*(((Z'*Z)\Z')*((center- V*a + W*r)+ (left-(V*a +W*r)*...
           b - k*d)*b + (right-(V*a + W*r)*g - k*h)*g))-s;
           ((a'*V' + r' * W' + s'*Z')*(V*a + W*r + Z*s))\(left'*(V*a +W*r + Z*s)...
            -(a'*V' + r'*W' +s'*Z')*k*d)- b;
           ((a'*V' + r' * W' + s'*Z')*(V*a + W*r + Z*s))\(right'*(V*a +W*r + Z*s)...
            -(a'*V' + r'*W' +s'*Z')*k*h)- g;
          (1/10*(left'*k -(a'*V' + r'*W' + s'*Z')*k*b))-d;
          (1/10*(right'*k -(a'*V' + r'*W' + s'*Z')*k*g))- h]

Walter Roberson 2018-8-7

在 MATLAB Online 中打开

function f = FIFON(x,V,W,Z,k,center,left,right)
a=[x(1);x(2);x(3);x(4);x(5);x(6)];
r=[x(7);x(8);x(9);x(10);x(11);x(12)];
s=[x(13);x(14);x(15);x(16);x(17);x(18)];
b=x(19);
g=x(20);
d=x(21);
h=x(22);
         f=[(1/(1+b^2 + g^2))*(((V'*V)\ V')*((center- W*r + Z*s)+ (left-(W*r +Z*s)*b...
         - k*d)*b + (right-(W*r + Z*s)*g - k*h)*g)) - a;
            (1/(1+b^2 +g^2))*(((W'*W)\ W')*((center- V*a + Z*s)+ (left-(V*a +Z*s)*...
             b - k*d)*b + (right-(V*a + Z*s)*g - k*h)*g)) - r;
           (1/(1+b^2 +g^2))*(((Z'*Z)\Z')*((center- V*a + W*r)+ (left-(V*a +W*r)*...
             b - k*d)*b + (right-(V*a + W*r)*g - k*h)*g)) - s;
             ((a'*V' + r' * W' + s'*Z')*(V*a + W*r + Z*s))\(left'*(V*a +W*r + Z*s)...
              -(a'*V' + r'*W' +s'*Z')*k*d) - b;
             ((a'*V' + r' * W' + s'*Z')*(V*a + W*r + Z*s))\(right'*(V*a +W*r + Z*s)...
              -(a'*V' + r'*W' +s'*Z')*k*h) - g;
            (1/10*(left'*k -(a'*V' + r'*W' + s'*Z')*k*b)) - d;
            (1/10*(right'*k -(a'*V' + r'*W' + s'*Z')*k*g)) - h];

Spacing matters.

Walter Roberson 2018-8-7

My tests suggest that there might be a solution near

[3.0764454923181308, -0.29750955941213153, 1.32522678326379184, -5.67281188388481006, 3.71962594859759532, 1.79157413120165088, 0.0913355342239042522, -3.3450226246250705, 2.5660435058715354, 0.0354122586159170138, -0.177027435264798, -1.15044309568988101, 1.65430815977474821, -1.10152163665358227, 0.626930903877788825, -0.316658524647466799, -0.740546143279594782, 0.803505679158440511, -44.5712374138825425, 2.09613318816875438, 149.797294636857373, -6.26552007745399386]

Because of the 22 dimensional nature of the problem, searching is expensive.

Honey Adams 2018-8-8