I've written a fixed-point number abstraction in anticipation of doing some work on devices without an FPU. I'd like to know what's required to use this abstraction with a few specific Eigen types. The specific types I would be using it with are:

Eigen::AngleAxis
Eigen::Matrix
Eigen::Matrix
Eigen::Matrix
Eigen::Matrix
Eigen::Quaternion

Is this simply a matter of specializing Eigen::NumTraits for my fixed-point type?

In addition to specializing NumTraits you would have to implement the math functions (MathFunctions.h), then you should be OK

Where things would become more tricky is if you wanted vectorization ... then you'd at least have to specialize the PacketMath.h functions.

bjacob wrote:In addition to specializing NumTraits you would have to implement the math functions (MathFunctions.h), then you should be OK

Thanks, that doesn't look too difficult

By the way, you don't need to specialize the functions that you don't use.

For many use cases, all you'll need to specialize is ei_sqrt, ei_abs, ei_abs2.

Cool, got it working and passing all my unit tests