Re: [R] problem with nlsLM.....

2019-03-20 Thread Ivan Krylov
On Wed, 20 Mar 2019 09:43:11 + akshay kulkarni wrote: > But doesn't removing some of the parameters reduce the precision of > the relationship between the response variable and the > predictors(inefficient estimates of the coefficients)? No, it doesn't, since there is already more variables

Re: [R] problem with nlsLM.....

2019-03-20 Thread Ivan Krylov
On Wed, 20 Mar 2019 08:02:45 + akshay kulkarni wrote: > formulaDH5 <- as.formula(HM1 ~ (a + (b * ((HM2 + 0.3)^(1/2 + > (A*sin(w*HM3 + c) + C)) The problem with this formula is simple: the partial derivative with respect to `a` is the same as the partial derivative with respect to `C`. Th

[R] problem with nlsLM function

2019-03-19 Thread akshay kulkarni
dear members, I am getting the "singular gradient error" when I use nls for a function of two variables: > formulaDH5 HM1 ~ (a + (b * ((HM2 + 0.3)^(1/2 + (A * sin(w * HM3 + a) + C) HM1 is the response variable, and HM2 and HM3 are predictors. The problem is I get the