On Saturday, 20 February 2016 at 15:00:50 UTC, jmh530 wrote:
On Saturday, 20 February 2016 at 13:31:03 UTC, bachmeier wrote:
On Friday, 19 February 2016 at 21:50:43 UTC, jmh530 wrote:
On Friday, 19 February 2016 at 21:10:45 UTC, Dave wrote:
Alternately, you could try calling pystan or rstan from D. If
you make any progress on these approaches, I would be
interested.
If it has an R interface, it also has a D interface using my
rdlang project. I will look at it when I get some free time.
R is the most popular way to use Stan I think. rstan is the
library.
I looked at rstan. I've heard of it but never used it. AFAICT,
the computationally intensive part is done by the call to stan()
from within the R code. Therefore there are no efficiency issues
with calling D -> R -> stan.
I took the easy road and ran the given R code directly. Here is
my program:
import rinsided, rdlang.r, rdlang.vector;
void main() {
evalRQ(`library(rstan)`);
evalRQ(`y <-
read.table('https://raw.github.com/wiki/stan-dev/rstan/rats.txt',
header = TRUE)`);
evalRQ(`x <- c(8, 15, 22, 29, 36)`);
evalRQ(`xbar <- mean(x)`);
evalRQ(`N <- nrow(y)`);
evalRQ(`T <- ncol(y)`);
evalRQ(`rats_fit <- stan(file =
'https://raw.githubusercontent.com/stan-dev/example-models/master/bugs_examples/vol1/rats/rats.stan')`);
auto stanOutput = RVector(evalR(`attr(rats_fit,
"sim")[[1]][[1]][[1]]`));
stanOutput.print();
}
stanOutput is a D struct holding a pointer to that particular
part of the output. Without more knowledge of rats_fit, I can't
go further. You could also pass D data into R (y, x, xbar, ...)
but I didn't see a reason to do that here. Nonetheless this is
what you want, a way to call rstan from D, and then access the
results from your D program.
