On Tue, Sep 15, 2009 at 5:28 AM, matt
<address@hidden> wrote:
Having said that, James found the vectorized code ran 5x faster on
his Matlab--so who knows what is going on? Perhaps the Matlab
compiler is cheating?
I wouldn't call working well cheating ;)
As it was explained to me when 7.0 came out, the JIT compiler is able to detect certain idioms and to replace them with very optimized code. In the 7.0 days it was pretty hit or miss whether the JIT optimizations would kick in or not and I remember at a training session that the application engineer from Mathworks described in great detail how to monkey around with loop structure and variable use in order to help the JIT detect the idioms. In the following years I imagine their idiom detection has improved substantially.
--judd