Truncate a floating point number without rounding up

Question

I have a floating point number that I want to truncate to 3 places but I don't want to round up.

For example, convert 1.0155555555555555 to 1.015 (not 1.016).

How would I go about doing this in Ruby?

Answer 1

Assuming you have a float, try this:

(x * 1000).floor / 1000.0

Result:

1.015

See it working online: ideone