search for: r_gcall

...ed only for internal use in implementation of optim called from R. Using opt_struct in my C code calling samin encounters the following problems: 1. The definition of opt_struct is present inside the file optim.c, thus my source has no access to it. 2. The function genptry uses opt_struct attribute R_gcall of type SEXP which doesn't allow to specify a function writen in C for generating a new candidate point. This should be either an R function or NULL, meaning that the default generating function is used. Hence, a C user has to copy the definition of opt_struct to his code and fill NULL to its...

...timgr gr, int *fail, void *ex, double factr, double pgtol, int *fncount, int *grcount, int maxit, char *msg, int trace, int nREPORT); What do I put for parameter ex (11th parameter)? I looked at optim.c codes at R sites and it's a structure that has bunch of objects such as SEXP R_fcall, SEXP R_gcall, SEXP R_env, double* ndeps, etc. I cannot figure out what it is about. How about fncount, rcount? R-ext.pdf or R help does not explain it in detail. Any comments would help. Thank you. [[alternative HTML version deleted]]

I'm preparing some code to compute the optimal geometry of stressed solids. The core of the calculations is the optimization of elastic energy using the simulated annealing method implemented in the R optim() rutine. I've defined a function to compute this "energy" scalar (the fn parameter for optim) and prepared a list with the arrays defining the geometry and the elastic