Choosing between a positive and negative number

[Kino]

Quick question, Im trying to randomize a fixed number to either be positive or negative.
(eg. Roll either +30 or -30, which is not the same as range from -30 to +30).

- Cant use 30*(-1 to 1) as it can roll 0.
- Is there a way to do this that does not involve (if then else) conditions?

 

[IcemanBo]

Arbitary formulas like "30 - ( 60 * (Random Integer from 0 to 1) )" can be used, but an IfThenElse is probably simpler to read.

 

[Pyrogasm]

30*((Random Int 0,1)-0.5)*2

But I’m not sure that’s more clear. You could write a custom function and just call it:

function RandSpread takes real val returns real
  return val*(GetRandomInt(0,1)-0.5)*2
endfunction

//for example
set udg_SomeVar = RandSpread(30.)

 

[Tasyen]

One also could fill an array with possible results and then roll an index. Then one reads the array's value from the rolled index.

Int[0] = 30
Int[1] = -30

set value = Int[GetRandomInt(0,1)]

If you just don't want to write the "if then else" in your code, there is a function in Blizzard.j that returns one of two values based on the given boolean.

function IntegerTertiaryOp takes boolean flag, integer valueA, integer valueB returns integer
    if flag then
        return valueA
    else
        return valueB
    endif
endfunction

set value = IntegerTertiaryOp(GetRandomInt(0,1) == 0, 30, -30)

 

[Dr Super Good]

Roll two numbers. Your random number and a random integer between 0 and 1 inclusive which one can call random sign. Use a global constant array which one can call sign map to map the random sign to either -1 or 1. Multiply your random number by the value of sign map contained at random sign.

This is likely the most efficient implementation in JASS.

 

[Kino]

30*((Random Int 0,1)-0.5)*2

This is the solution I ended up using.