标题: 求助:关于SAS的数值精度 [打印本页] 作者: shiyiming 时间: 2004-4-18 18:05 标题: 求助:关于SAS的数值精度 我做计算用到500**500,SAS无法计算了
我知道MATHMATIC可以轻松计算700**2000,不知道SAS的数值范围有多大,及如何调整精度,多谢了作者: shiyiming 时间: 2004-4-19 21:45
I think your question has nothing to do with accuracy, it is overflow in floating point representation in numerical analysis. I really doubt that MATHMATICA can handle 700**2000, the number may well beyond the number of the nuclei in this universerse. If you really need to handle this kind of case, you have to take a Logarithm and transform your model. In fact, the direct attack on a number in this range generally mean nothing.作者: shiyiming 时间: 2004-4-20 23:33
多谢xic,确实是超过了浮点数的存储范围了,要算这个只能另寻它法了 <!-- s:? --><img src="{SMILIES_PATH}/icon_confused.gif" alt=":?" title="Confused" /><!-- s:? -->