Yeah just make sure it's not negative before you square root it.

you mean like checking if a number is negative before trying to take its root?...

if (x >= 0)
//take root
else
//don't take root OR multiply by -1, then take root OR something

EDIT: ninja'd by Ferret. :o

hmm, I don't do A level maths so I can't remember the correct term, but I don't just mean the square of a negative, I mean things like division by zero, infinity etc.

I want the user to enter a string (an equation), which is converted to code, then checked to see if it is possible to execute, before executing it.

Then make sure the denominator isn't equal to zero...? Idk sounds like you just need an if statement but I'm not even sure about what you are talking about.

It's for things like this that I become upset with GM for not having exception handling.

Use sqrt(abs(value))

I basically just want to make sure that the answer to the equation is a real number that the computer can understand.

Sorry, I am obviously not very knowledgeable about this, but I am curious.

I agree with Taizen, surely just use a modulus function (ie abs()) to make it real? On the other hand, you could check if x<=0. Finally, if it's something mathematical like quadratic formula there is a method of checking if there a real solutions... but if its not mathematical like that I won't type it haha

Imaginary numbers only show up if you square root a negative number. In math it's best to separate the negative by taking out negative 1 like so: sqrt(-4) => sqrt(4*(-1)) and then get 2i and i=sqrt(-1). In GM, if you don't want to deal with imaginary numbers just make sure you use absolute values in the square root (ie, abs(x)).

@matty, it's fine if x=0, just can't be negative.

Opps I meant to say check if x>=0 and then the operation can go ahead. And I thing the easiest thing to do would be abs(), then use other parameters to check if the event is allowed in game.

hmmm. ok, don't worry maybe this problem was... imaginary

PAHAHAHA i'm so punny.

i should brutally assassinate your face for that comment, Moikle.

:P but yeah, the problem still stands of checking for the square roots in an equation the user enters in order to replace the value with it's absolute value.

So the user is entering entire equations?

well, sort of. For graphing, I am just experimenting