Hi Eliot: > On 03 Apr 2015, at 16:47, Eliot Miranda <[email protected]> wrote: > > if seed is Andes with 16rffffffff when it is initialized then the Java code > can be used to generate the next value and the sign conversion only applied > once to yield the next value. That would eliminate lots of conversions and > make the code readable, right?
Sorry, I don’t understand you. In the Java code the `0xffffffff` is redundant/superfluous. It’s there because I ported the code from JavaScript. The important part is that Java has signed 32bit integers. So, it works as expected out of the box. The SOM version shows the explicit operations you need if you don’t have any knowledge about the underlying integer representation. In most SOM implementations, integers happen to be represented as 64bit values, that overflow into some form of big/large integer representations. The sign-related operations are necessary to get the correct shift and overflow semantics. I guess I could implement it easily on a 64-bit Spur image, but I haven’t looked into that yet. Marcus’ comment looks also useful, but it is going to be very slow… Best regards Stefan -- Stefan Marr INRIA Lille - Nord Europe http://stefan-marr.de/research/
