I don’t have a link to a website in my head right now, but any way, here are some examples:
1- Never use variables less than 32 bit width if you are interested in performance: consider that a and b are both short integers statement like a = a+b is valid in C but not in Java; because Java promotes all variables to 4 bytes before ANY operation (even comparative reading [non modifying] operations). This way, both a & b will be promoted to int, and summed, then an explicit cast is required before being assigned back to the variable a. All this overhead is not required in processing-oriented applications. BTW although a= a+b won’t work , a+=b will work (because it includes an implicit casting operator) 2- Remember that all variables in java are signed (except for char which is equivalent to unsigned short in C) and that variables in Java have different sizes than C so comparing the literal 0xFFFF to the short variable a whose value is 0xFFFF won’t return true..try it. Did you get why? to overcome this problem you will lose some of the performance too. 3- Remember that not all operators do the same action in Java like in C: revise the function of the >> operator in java versus C. One final point: my name is “Amr” not “Arn”. Regards Amr From: Dragos-Bogdan Sima Sent: Wednesday, March 28, 2012 7:05 AM To: Amr AL-Hossary Cc: Andreas Prlic ; Biojava ; Scooter Willis Subject: Re: [Biojava-l] [Biojava-dev] Port an Algorithm to Java Hello Dr. Andreas Prlic, So basically I have to understand how the programs are working while overviewing the sources, so that I could explain in my aplication how I plan to port to Java? And Arn, could you explain me a little bit more the cases where the PTM would be required or give me some usefull links, beside the wikipage, for study? Thanks you, Dragos. _______________________________________________ Biojava-l mailing list - [email protected] http://lists.open-bio.org/mailman/listinfo/biojava-l
