About Erlang's rounded up and rounded down

In the Erlang API, Erlang: trunc/1 is nearest integer, and Erlang: Round/1 is rounding,

Sort it out: positive numbers are rounded up and down,

1% % rounded up to 2 Ceil (N)-> 3 T = trunc (N), 4 case n = T of5 true-> T; 6 false-> 1 + T7 end.

1% % rounded down to 2 floor (x)-> 3 T = trunc (x), 4 case (x <t) of5 true-> T-1; 6 _-> T7 end.

 

The rounded up and down of negative numbers can be used in all numbers (including positive numbers and negative numbers) with a slight flexibility ):

% Is the smallest integer Ceil (x)-> T = trunc (x), if X-T = 0-> T; true-> If x> 0-> T + 1; true-> T end.

 

% Integer floor (x)-> T = trunc (x), if X-T = 0-> T; true-> If x> 0-> T; true-> T-1 end.