Dear List-Members, since 3 weeks I have been heavily working on reproducing the results of an economic paper. The method there uses the numerical solution of an integral within nonlinear least squares. Within the integrand there is also some parameter to estimate. Is that in the end possible to implement in R [Originally it was done in GAUSS]? I'm nearly into giving up.
I constucted an example to showing the problems I face. I have three questions - related to three errors shown below: 1) How to make clear that in the integrand z is the integration variable and b1 is a parameter while x1 is a data variable 2) and 3) How to set up a correct estimation of the integral? library(stats) y <- c(2,15,24,21,5,6,) x1 <- c(2.21,5,3,5,2,1) x2 <- c(4.51,6,2,11,0.4,3) f <- function(z) {z + b1*x1} vf <- Vectorize(f) g <- function(z) {z + x1} vg <- Vectorize(f) Error 1: > nls(y ~ integrate(vf,0,1)+b2*x2,start=list(b1=0.5,b2=2)) Error in function (z) : object "b1" not found Error 2: > nls(y ~ integrate(vg,0,1)+b2*x2,start=list(b1=0.5,b2=2)) Error in integrate(vg, 0, 1) : REAL() can only be applied to a 'numeric', not a 'list' Error 3: > nls(y ~ integrate(g,0,1)+b2*x2,start=list(b1=0.5,b2=2)) Error in integrate(g, 0, 1) + b2 * x2 : non-numeric argument to binary operator In addition: Warning messages: 1: longer object length is not a multiple of shorter object length in: z + x1 With a lot of thanks in advance, Michael ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.