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
1.0155555555555555
1.015
Assuming you have a float, try this:
float
(x * 1000).floor / 1000.0
Result:
See it working online: ideone