??? Subscripted assignment dimension mismatch.

function [er]= ErrorF(x,y,p)

x=[-0.6 -0.4 -0.1 0.5 1.5];
y=[18 8 3 2 0.9];
er=y-(1./((x.*p(1))+p(2)));

end

ERROR:

??? Subscripted assignment dimension mismatch.

Error in ==> fminsearch at 191
fv(:,1) = funfcn(x,varargin{:});

Error in ==> Untitled at 3
p=fminsearch(@(p)er,[0.2 0.5])

need help with this.!!!!!

Answer 1

[Walter Roberson]

You call fminsearch on @(p)er but you are not passing p to er. You have not shown the code for er; you have instead shown the code for ErrorF. If you have created a variable named "er" before the fminsearch() call, by calling ErrorF yourself, then notice that variable would be a scalar rather than a function.

Question: why would you pass x and y to ErrorF if you are going to immediately reassign their values?

Suggested code:

x=[-0.6 -0.4 -0.1 0.5 1.5];
y=[18 8 3 2 0.9];
ErrorF = @(p) y-(1./((x.*p(1))+p(2)));
pval = fminsearch(ErrorF, [0.2 0.5]);

Answer 2

[Andrei Bobrov]

try this is code

x=[-0.6 -0.4 -0.1 0.5 1.5];
y=[18 8 3 2 0.9];
fun1 = @(p,x)1./(x.*p(1)+p(2));
pout = nlinfit(x,y,fun1,[.2 .5]);

x1 = linspace(-.6,1.5,100);

plot(x,y,'ko',x1,fun1(pout,x1),'r-')