frameRate is not setting the correct frame rate

This code calculates the frame rate.
```
var frames = 180; // set it below the maximum frame rate
frameRate(frames);
var data = [millis()];
draw = function() {
println(1000*data.length/(millis()-data[0])); // Frame rate taking the last 100 frames into account
println(1000/floor(1000/frames)); // Calculated frame rate according to theory
//println((millis()-data[0])/data.length);
data.push(millis());
if (data.length>100) {
data = data.slice(1);
}
};
```
However, the actual frame rate is close to the 1000/floor(1000/frameRate) when you run this code.

I suspect it might be something to do with setInterval or setTimeout not allowing non-integer values, and rounding the interval downwards.

Start by running the provided frameRate(180) example in the browser-based live editor and inspect the frameRate implementation, especially its setInterval or setTimeout scheduling. Confirm the measured rate and the calculated 1000/floor(1000/frameRate) value, then consider the issue done when the requested frame rate is applied without the observed downward rounding.

Written by the indexing model from the issue text.