Error using lsqcurvefit: Function value and YDATA sizes are not equal.

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Max De Chastelain
回答： Matt J 2021-4-4
I am trying to use the lsqcurvefit function to fit a sine wave to a data set, however i get the following error:
Function value and YDATA sizes are not equal.
when running the following code:
A = 0.3;
omega = 1;
phi = 0.1;
c = 0.1;
constants = [A omega phi c];
fun = @(timearray,constants) A .* (sin((timearray .* omega) + phi)) + c;
fittedconstants = lsqcurvefit(fun,constants,timearray,anglearray);
plot(timearray,fun(timearray,fittedconstants));
The array "timearray" is a 1x10001 double, defined by:
timearray = 0:0.01:100;
and the "anglearray" is also a 1x1001 double, filled with experimental data.
I feel as if it may be due to the mathematical operators used in my function, I have tried removing the "." before the "*" but this doesn't seem to work. placing a "." before and after the "sin" operator yields more errors.
Cheers in advance, I hope the information given is enough for a solution.
  1 个评论
Max De Chastelain
Max De Chastelain 2021-4-4
Checking the size of "fun" and "anglearray" yields the following:
>> size(fun)
ans =
1 1
>> size(anglearray)
ans =
1 10001
I am unsure as to how to get the size of "fun" to be a 1x10001 double.

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采纳的回答

Matt J
Matt J 2021-4-4
A = 0.3;
omega = 1;
phi = 0.1;
c = 0.1;
initialGuess = [A omega phi c];
fun = @(x,timearray) x(1) .* (sin((timearray .* x(2)) + x(3))) + x(4);
fittedconstants = lsqcurvefit(fun,initialGuess,timearray(:).',anglearray(:).');
plot(timearray,fun(fittedconstants, timearray));

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