fsolve, In an assignment A(:) = B, the number of elements in A and B must be the same.

Hi All, my code is:

format long;
pvals = 10:0.2:14; 
nump = length(pvals);
m = zeros(1, nump);n = zeros(1, nump);z = zeros(1, nump);
for pidx = 1 : nump
    p = pvals(pidx);
    spdf = @(x) 3.*(50.^3)./(x+50).^(3+1)./(1-(50./(50+50)).^3);
    fun2 = @(x,z) min(x,max(0,fzero(@(y) (100-p-x+y).*(2.*z(2)+4.*z(1).*y).^2-1,1E-6))).^2.*spdf(x); 
    fun3 = @(z) integral(@(x) fun2(x,z),0,50,'arrayvalued', true);
    fun21 = @(x,z) min(x,max(0,fzero(@(y) (100-p-x+y).*(2.*z(2)+4.*z(1).*y).^2-1,1E-6))).*spdf(x); 
    fun31 = @(z) integral(@(x) fun21(x,z),0,50,'arrayvalued', true);  
    m(pidx)=fsolve(@(z)[fun31(z)-10; fun3(z)-178.57145], [0.02; 0.04]);
    fun44= @(z) integral(@(x) (100-p-x+min(x,max(0,fzero(@(y) (100-p-x+y).*(2.*z(2)+4.*z(1).*y).^2-1,1E-6)))).^(0.5).*spdf(x),0,50,'arrayvalued', true);
    n(pidx)=feval(fun44,m(pidx));
    z(pidx) = n(pidx) - integral(@(x) (100-x).^0.5.*spdf(x),0,50);
end
plot(pvals, z, 'd');

The error is:

In an assignment A(:) = B, the number of elements in A and B must be the same.

Error in FinalCaseCCPareto (line 61)
    m(pidx)=fsolve(@(z)[fun31(z)-10; fun3(z)-178.57145], [0.02; 0.04]);

I think the error comes from the fact that, this line of code, m(pidx)=fsolve(@(z)[fun31(z)-10; fun3(z)-178.57145], [0.02; 0.04]) will return two numbers. I have tested that all the other parts are correct. Anyone can help me fix the code? Thank you in advance!

Answer 1

[Matt J]

m(pidx,1:2)=fsolve(@(z)[fun31(z)-10; fun3(z)-178.57145], [0.02; 0.04]);

[James_111]

Thanks, Matt! I changed it. But a new error comes as:

Error using fzero (line 306)

FZERO cannot continue because user-supplied function_handle ==> @(y)(100-p-x+y).*(2.*z(2)+4.*z(1).*y).^2-1 failed with the error below.

Index exceeds matrix dimensions.

Do you have some idea?

[Matt J]

Same thing ...

n(pidx)=feval(fun44,m(pidx,1:2));

[James_111]

Thanks, Matt!