origin怎么把好几条应力应变曲线进行自定义非线性拟合,公式为y =10*(A(x/0.002)-B(x/0.002)

origin怎么把好几条应力应变曲线进行自定义非线性拟合,公式为y =10*(A(x/0.002)-B(x/0.002)^2),
这些错误啥意思
E:originOriginCNLSF_nlfyingbian.fit(37) :Error,function or variable A not found
E:originOriginCNLSF_nlfyingbian.fit(37) :Error,general compile error
E:originOriginCNLSF_nlfyingbian.fit(28) :Error,error(s) found in compiling function _nlsfyingbian
Compile Failed!