拟使用模型公式为Y=exp(a*x^b),以下是脚本及计算结果:
cl<-data.frame(
- X=c(95.3, 87.18, 44.94, 26.36, 18.12, 84.68, 37.24, 33.04, 23.46, 9.72, 97.92, 71.44, 44.52, 24.44, 15.26),
- Y=c(521.5, 689.78, 1284.71, 2018.8, 2560.46, 524.91, 989.05, 1646.32, 2239.65, 2972.96, 478.54, 875.52, 1432.5, 2144.74, 2629.2)
- ) nls.sol<-nls(Y~exp(a*X^b), data=cl) Error in nls(Y ~ exp(a * X^b), data = cl) : 循环次数超过了50这个最大值 此外: Warning message: In nls(Y ~ exp(a * X^b), data = cl) : No starting values specified for some parameters. Initializing ‘a’, ‘b’ to '1.'. Consider specifying 'start' or using a selfStart model 问题:循环次数超过了50这个是因为什么?是否影响参数的估计?另外start参数里a,b起始值是如何设定的