error using fzero in a loop

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Tristan 2013-10-20

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评论： dpb 2013-10-21

I'm trying to find all the points between 0 and 10 where the derivative of y=0 by using (x1(H)+x2(H))/2) as a staring point but I keep on getting this error... Please help :(

Error using fzero (line 169) If FUN is a MATLAB object, it must have an feval method.

h=10;

ti=(1/200);

n=[1.2 2.9];

ni=[1 3];

na=[2 1];

x=[];

for k=1:numel(n)

x=sort([x (((0:1:1+(ceil(h/(n(k)))))-0.5)*(n(k)))]);

end

x1=(x(1:numel(x)-1));

x2=(x(2:numel(x)));

for T=[1:10];

nwa=[na.*sin((T*ti)*(pi./(ni)))];

for H=(1:numel(x1))

syms d;

y=sum(nwa.*cos(d.*(pi./n)));

X(H)=fzero(diff(y),(x1(H)+x2(H))/2);

end

P=(X(X>x1<x2))';

end

采纳的回答

dpb 2013-10-20

0
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在 MATLAB Online 中打开

From the doc's for fzero

X = fzero(FUN,X0) ... FUN is a function handle.

Your code is

X(H)=fzero(diff(y),(x1(H)+x2(H))/2);

where you've entered an actual function.

I'm trying to find a way to calculate the position of the antinodes (the maximas and minimas) of a waveworm=sum(nwa.*cos(d.*(pi./n))) by using its derivative, and then using fzero starting at all the midpoints between consecutive multiples of n between 0 and 10.