求救，MATALB中NaN
在matalb中， 下面程序：a=nan
if a==nan, a=2; end
a
结果为什么a仍然是NaN呀？
[ 本帖最后由 ChaChing 于 2009-5-16 17:59 编辑 ] Because two NaNs are not equal to each other, logical operations involving NaNs always return false, except ~= (not equal). Consequently,
NaN ~= NaN
ans =
1
NaN == NaN
ans =
0
and the NaNs in a vector are treated as different unique elements.
unique()
ans =
1 NaN NaN
Use the isnan function to detect NaNs in an array.
isnan()
ans =
0 0 1 1
下次请先在matlab帮助中搜索一下
[ 本帖最后由 ChaChing 于 2009-5-16 18:02 编辑 ] 谢谢，太懒了我
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