fix printing of Float in observe (reported by Valentin Gjorgjioski).
fix printing of Float in observe (reported by Valentin Gjorgjioski).

I missed this when I split the representations of Float and Double.

FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs,FranklinChen/Hugs