MATLAB fittype函数报错显示Problem parameter i does not appear in the equation expression.
请问这要怎么改
拟合公式如下
ft = fittype(@(a,b,c,d,e,i,j,k,x) a+b*(x-i)+c*(x-i).*tanh((x-i)/k)+d*(x-j).*tanh((x-j)/k)+e, 'independent', 'x', 'dependent', 'y','problem',{'i','j','k'}, 'coefficients',{'a','b','c','d','e'});
[fitresult, gof] = fit( x12, c12(91:end), ft, 'problem', [300,450,1e-5] );