Infinity Yamato Nan

In data statistics, it is important to understand infinity and Nan, and to paste a basic concept.

When index e is all 1 o'clock, IEEE 754 provides such storage as a special use, not as a normal data. Infinity e=255 m=0, used as infinity (or infinity, ∞). 　　According to the different symbols, there are +∞,-∞. Infinity can be calculated by arithmetic, and the following are examples of operations on Infinity: 1/∞= 0, -1/∞=-0, 1/0 =∞, -1/0 =-∞</pre> nan e=255, m not 0 o'clock, used as Nan (not a number 　　, "not a few" meaning). 　　When illegal operations are performed on the data (for example, 1 squared), the result appears nan. 　　When the operation contains Nan, the result must also be Nan. Note: Nan<>nan. 　　It is meaningless to compare Nan to each other. (Nan also has the use of Qnan and Snan for programs to catch certain exception states.) See also Nan entry)