Fixed-point arithmetic

Question

Does anyone know of a library to do fixed point arithmetic in Python? Or, does anyone has sample code?

Answer 1

If you are interested in doing fixed point arithmetic, the Python Standard Library has a decimal module that can do it.

Actually, it has a more flexible floating point ability than the built-in too. By flexible I mean that it:

• Has "signals" for various exceptional conditions (these can be set to do a variety of things on signaling)

• Has positive and negative infinities, as well as NaN (not a number)

• Can differentiate between positive and negative 0

• Allows you to set different rounding schemes.

• Allows you to set your own min and max values.

All in all, it is handy for a million household uses.

Answer 2

Another option worth considering if you want to simulate the behaviour of binary fixed-point numbers beyond simple arithmetic operations, is the spfpm module. That will allow you to calculate square-roots, powers, logarithms and trigonometric functions using fixed numbers of bits. It's a pure-python module, so doesn't offer the ultimate performance but can do hundreds of thousands of arithmetic operations per second on 256-bit numbers.

Answer 3

The deModel package sounds like what you're looking for.