Ross Boylan <[EMAIL PROTECTED]> writes: > I have some calculations that require persistent state. For example, > they retain most of the data across calls with different parameters. > They retain parameters across calls with different subsets of the cases > (this is for distributed computation). They retain early analysis of > the problem to speed later computations. > > I've created an S4 object, and the stylized code looks like this > calc <- makeCalculator(a, b, c) > calc <- setParams(calc, d, e) > calc <- compute(calc) > results <- results(calc) > The client code (such as that above) must remember to do the > assignments, not just invoke the functions. > > I notice this does not seem to be the usual style, which is more like > results <- compute(calc) > > and possibly using assignment operators like > params(calc) <- x > (actually, I have a call like that, but some of the updates take > multiple arguments).
I think the setReplaceMethod approach has some advantages in the sense that you don't have to remember to capture the return. You can handle multiple parameters in a couple of ways: params(calc, p="num_iter") <- 1000 params(calc, p="verbose") <- FALSE params(calc) <- list(num_iter=100, verbose=FALSE) + seth ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
