-Inf

what is meant by -Inf?

Answer 1

[Walter Roberson]

http://www.mathworks.com/help/techdoc/ref/inf.html

-Inf is the unary negation operator applied to Inf, which is Positive Infinity. -Inf is thus negative infinity.

Some operations that would produce numbers more negative than the most negative number that can be represented in binary floating point, will indicate that numeric overflow by using -Inf as the answer.

-Inf is, among other things, the result of log(0)