y = x * 1e+20

[tgtsuru]

Dear Hoy Moon,

I have a question, again.

I set an equation of y = x * 1e+20.
I input x = 1 then I got y = 1e+20.
However, input y = 1 then I got just x = 0.
Could you tell me how to reach the correct ansower of x=1e-20.
Note that setting Variable Precision and Constant Precision at maximum
did not change the situation.

Regards,
T.Tsuru

[hoymoon]

Hello T. Tsuru,

Thank you for sharing another observation.

Formulaic uses a "numerical" approach to find a solution to an
equation. It repeatedly evaluates the equation, trying different input
values. It stops, and displays the last input value it tried as the
"answer", when it believes that further tries will not improve the
accuracy any further.

The current version of Formulaic considers "seven decimal digits" of
accuracy sufficient to end the search for a more accurate answer.

When investigating, we did however discover a problem with how "seven
decimal digits" of accuracy is implemented in the current version.
Rather than look for seven correct digits of mantissa (which is what
it should do), Formulaic is currently hard-coded to an accuracy of
1e-7. For a very large number of equations, this achieves the desired
result, but for your sample equation, it doesn't.

We'll fix this issue with the next version of Formulaic, so that "x
decimal digits of accuracy" is correctly implemented.

Kind regards,
Hoy Moon