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楼主 |
发表于 2009-11-21 10:35 PM
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书中这一段:
“Lately, I have begun to understand what a trading model with no free parameters
means. It doesn’t mean that it does not contain, for example, any
lookback period for calculating trends, or thresholds for entry or exit. I think
that would be impossible. It just means that all such parameters are dynamically
optimized in a moving lookback window.”
说的应该是步进式(walk forward)优化测试方法。Chan 似乎很晚才知道这一方法。他下面又说:
“Now, it is quite computationally challenging to optimize all these parameters
just in time for your next order, but it is often even more difficult to do that
in a backtest, given that a multidimensional optimization needs to be performed
for each historical bar. As a result, I personally have seldom traded parameterless
models。”
这也许是他用 Matlab 的缺陷。对于复杂的非标准数学程序来说,Matlab 太慢。 |
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