> I've been reading some code from an example in a blog post (
> http://www.maxdama.com/ here ) and I came across an operator that I hadn't
> seen before. The author used a <<- operator to update a variable, like so:
> ecov_xy <<- ecov_xy+decay*(x[t]*y[t]-ecov_xy)
> At first I thought it was a mistake and tried replacing it with the usual <-
> assignment operator, but I didn't get the same results. So what does the
> double arrow <<- operator do?
It is a "super assignment" operator, which means that the assignment is done in the global environment, rather than to a variable that is within a function and therefore may only have local scope.