Hey guys, this is going to be a very silly question but what does != mean? In one of my stats course, the prof used != in one of his notes and I have no clue what it means, I asked around as well. ex. n1 != n2 Thanks.
I.... don't think it means anything... Maybe he just wanted to emphasize it to all the non-attentive people.
maybe it mean n1 !(factorial) = n2 ex. if n1 equaled 4 4! = n2 4 x 3 x 2 x 1=n2 24 = n2 At least in math the ! usually means factorial
To be exact, != is "not equal to" in C or C++. I don't know the reason why he is using it in Stat. May be he also teaches programming.
It's the factorial notation. For any positive integer n, n! literally means taking the product of [n*(n-1)*(n-2)*....*2*1] Basically you take the number n and you continue to multiply by the next lesser integer until you reach 1. i.e. 5! = 5*4*3*2*1=120 I'll bet you are going through combinations and/or permutations right now?
Nope. Hypothesis testing and regression right now. I guess the prof used "n1 != n2" because he was too lazy to copy and paste the actual inequality. Lol
n1 != n2 Not equal under C/C++ Perhaps he has never used the inequality sign (≠) for writing these notations. You'll perhaps often sees people writing them using ~=, which is a MATLAB standard notation for not equal. Many programmers will do this to you for several different things n1+=n2 (n1=n1+n2) n1-=n2 (n1=n1-n2) n1*=n2 (n1=n1*n2)
Since it's hypothesis testing, it's the "not equal to" sign. I'm guessing the notes in the course are electronic instead of handwriting, and that the teacher didn't use Latex to type it out. If the teacher meant to write the "not equal to" sign on the board then it would have been easier to make an equal sign and then cross it.
It'd only be easier in Latex, but you don't have to use Latex to do so MS office have an Equation tool which can do this, or you can look it up using Character Map After all.. it's all UNICODE characters
