2 releases
Uses old Rust 2015
0.0.2 | Mar 12, 2017 |
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0.0.1 | Mar 10, 2017 |
#17 in #propagation
15KB
526 lines
err_prop
Super simple ( and stupid ) floating point type calculating upper bound of error propagation I dont guarantee that this is correct. If you know you can do something better just contribute! :)
how it works
This works on premise that each floating point operation has an error. Where Addition and Subtraction generate actual error and Multiplication Division just increase that error: snapshot of implementation:
Add:
val: self.val + rhs.val,
err: self.val.abs().max(rhs.val.abs()) + self.err + rhs.err
Sub:
val: self.val - rhs.val,
err: self.val.abs().max(rhs.val.abs()) + self.err + rhs.err
Mul:
val: self.val * rhs.val,
err: self.val.abs() * rhs.err + rhs.val.abs() * self.err
Div:
val: self.val / rhs.val,
err: self.err / rhs.val.abs() + rhs.err * self.val / (rhs.val * rhs.val)
After you are done with your calculations use the .err()
method or better .err_times_eps()
to get static upper bound value of accumulated error
bunch of method unimplemented!()
There is bunch of methods which are unimplemented!(). Why? Because I needed to provide them however I did not them yet, so I just put unimplemented!().
Most important std::ops::* are implemented that is:
+, - , *, /
why cgmath dependency?
Well. Because I am using cgmath library. and unfortunatelly to be able to use custom num type with cgmath you have to depend on them. :( Because they provide their own trait which has to be implemented.
Dependencies
~1.5MB
~23K SLoC