Why do I get non-integer numbers when using script?

[Hey Evgenii]

Hi guys, I am trying to build a simple script that sets keyframes automatically every 'i' seconds and changes  position by fixed amount of pixels ( in my case -640) on every keyframe. 

I wrote a simple lines of code to do it: 

var curX = 320.0;
    for (i = 10; i <= 240; i += 5){

    selection[0].setValueAtTime(i, [curX,540])
    curX += -640.0;
};

But all values of every keyframe are non-integer numbers, although in the code above there are only integers. Here is the some values I get when running the code:

10 sec position x:320 y: 540;

15 sec position x:-321,9194 y: 540;

19,29 sec position x:-958,29 y: 540;

24.29 sec position x:-1598,9316 y: 540;

......

....

0;02;59;27  position x: -21433,1681 y: 540;

selection in this code is app.project.activeItem.selectedProperties, so selection[0] is position

Any suggestion why is this happening and how to fix?

Thank you in advance 🙂

[Mylenium]

Integers can be perfectly used to represent fractional numbers. That's a general misunderstanding many people have. If you want whole numbers, simply add a Math.round().

Mylenium

[Hey Evgenii]

I did
var curX = Math.round(320.0);

for (i = 10; i <= 240; i += 5){

selection[0].setValueAtTime(i, [Math.round(curX),540])

curX += Math.round(-640.0);

};

but it gives the same result

[Mylenium]

Well, then straighten out your math further by using timeToFrames() and such or additional rounding.

Mylenium

[Mathias Moehl]

How do you check the value of the keyframe? Do you read the value shown in the time-line? Do you see the same value in the dialog that pops up when you double-click on a keyframe?

If you see clean int numbers in the dialog, but point numbers in the timeline, then most likely your keyframes are not exactly at the start of a frame, but in-between frames.

If your comp has a frame rate of 23.976 fps, for example, and you insert a keyframe at 1s, then this keyrame sits a tiny bit before the (beginning of the) 25th frame, (since after 1s only 23.976 and not full 24frames have been played, yet).