Testing for NaN

SylvainGa over 1 year ago

Hi, how does one test for NaN? The following if statement is skipped, although 'rad' is NaN

Lang.NaN doesn't work either (doesn't compile). "try/catch" doesn't catch it either.

Thanks.

Top Replies

FlowState over 1 year ago in reply to SylvainGa +2 verified
That's bizarre but I think I found a workaround for you.

System.println(Math.acos(45d).toFloat().equals(Math.acos(45))); // true
```
class MathIsFun {
    static const negativeNan as Float = Math.acos…
```

Travis.ConnectIQ 6 months ago +2

I think this should work.

const FLT_MAX = 3.4028235e38f;

function isnan(x as Float) as Boolean {
    return x != x;
}

function isinf(x as Float) as Boolean {
    return (x < -FLT_MAX || FLT_MAX…

SylvainGa over 1 year ago in reply to FlowState +1

LOL, now try this:

If I manually set it to NaN, it works with your code, but when it's returned through a Math function, nope! WTH!

All Replies

0 SylvainGa over 1 year ago in reply to FlowState

Hard to find one when even this returns false :-(

+1 FlowState over 1 year ago in reply to SylvainGa

That's bizarre but I think I found a workaround for you.

System.println(Math.acos(45d).toFloat().equals(Math.acos(45))); // true

class MathIsFun {
    static const negativeNan as Float = Math.acos(45); // (add ".toFloat()" to make type checker happy)
    public function isFinite(val as Number or Long or Float or Double) as Boolean {
        var valAsFloat = val.toFloat();
        // this assumes that Infinity/-Infinity aren't possible in Monkey C.
        // if they are, we need to find a way to produce those values
        // (division by zero produces an error or exception)
        return !valAsFloat.equals(NaN) && !valAsFloat.equals(negativeNan);
    }
}

0 SylvainGa over 1 year ago in reply to FlowState

Yep, that did the trick, thanks again :-)

0 Travis.ConnectIQ 6 months ago

I think this should work.

const FLT_MAX = 3.4028235e38f;

function isnan(x as Float) as Boolean {
    return x != x;
}

function isinf(x as Float) as Boolean {
    return (x < -FLT_MAX || FLT_MAX < x);
}