On Friday, August 15, 2014 2:21:05 PM UTC-4, Neal Becker wrote: > > I'm trying to do numerical integration. I want a function that has state > information. > > Let's say I'm trying to integrate some function F over x. In addition, F > has > some state > > function F (x, state) = <do something with x and state> > As others have pointed out, the simplest solution here is a closure: integrate(x -> F(x,state), ...)
In python (and in c++), one way is to make F a class (which can have > state), and > overload the function call operator. Then this can be passed to the > numerical > integrator. > This solution always amazes me, considering that Python has closures (and now C++ has lambdas), and the closure solution is vastly simpler. (In my NLopt Python interface, I often field similar questions about how to pass extra state, so I feel like there is a cultural blindness in CS these days to closures, probably stemming from historical limitations of C++ etc.)
