Fastest way to compare values?

[StingRay]

Hi! Very often i have to compare mathematical expressions in loops. to speed them up, i first store the expression result in a value.
Then i compare this value with another - I'm looking for the most effective way to do that - now my question:

is it faster to compare

a) 2 counters
b) 2 Alterable Values
c) 2 Global Values

?

Thanks for your suggestions

[happygreenfrog]

I think that they would all be equally fast, except for maybe a counter, which would be slower as long as it isn't a hidden counter, as it would also need to display an object in addition to holding the values. If you made it a hidden counter, then it would probably be faster. Also, another thing to note is that directly comparing the mathematical expressions might actually be even faster. Over all, though, such minor things aren't going to affect performance significantly at all, so you should probably do it in the way that is most readable to you.

[StingRay]

Just an example, Happygreenfrog:

I've about 200 shops and calculate the distance from the user in a loop by:

((ACos(Sin(value( "lat1" ))*Sin(Lat( "data" ))+Cos(value( "lat1" ))*Cos(Lat( "data" ))*Cos(Lon( "data" )-value( "long1" )))*6371.0)/180.0*3.141592654)+((ACos(Sin(value( "lat1" ))*Sin(Lat( "data" ))+Cos(value( "lat1" ))*Cos(Lat( "data" ))*Cos(Lon( "data" )-value( "long1" )))*6371.0)/180.0*3.141592654)/5.0+1.0)

if i replace the value Lat("data") with the REAL value [ValAtXY( "Array", 6, LoopIndex("write")+2))] it would effect performance, i think.

[happygreenfrog]

With a long calculation like that, I can see what you mean. Okay, then, I think an alterable value would be the best way to go, then, unless you need the data to be carried from frame to frame, in which case, you should use a global value.

[Popcorn]

I did a simple test where I run a loop 500.000 times and add 1 to either a global value, a counter or an alterable value.

Results when adding:
Global Value: 11fps
Alterable Value: 9fps
Hidden Counter: 7fps
Number Counter: 3fps

However, when comparing values instead of adding I get these results:

Results when comparing:
Global Value: 20fps
Alterable Value: 40fps
Counter: 40fps

So it seems Alterable values and counters are both equally good when comparing values and is the preferable choice.

[StingRay]

great test, Popcorn! thanks alot! i think this will be a great ressource

btw: how do you get a FPS when a loop is running?

[Looki]

For one thing you could precalculate all values that are used twice, StringRay (the sin/cos stuff). Also, constant expressions such as 1.0/180.0*3.141592654 = 0.01745329252

[Popcorn]

how do you get a FPS when a loop is running?

You don't. Simply check the fps after the loop is finished.
Always: Run loop 500.000 times
Always: Set Counter to Framerate

[StingRay]

Thanks for the find, Looki!

[Pixelthief]

Using mathematics in the expression editor can indeed be more efficient than redundant object scoping and comparisons
Just make sure to write yourself a comment that says exactly what that line of code is doing and what those formulas or for, otherwise this is an incomprehensible mess: