Finding small equation solutions with great precision with Solvesys and Longfloat

[math7]

(07-25-2020 01:29 PM)John Keith Wrote:  Like most HP 50 applications (and built-in functions), SolveSys works with 12-digit floating-point numbers. LongFloat defines a new data type which is not compatible with existing commands and functions. This is why LongFloat has its own functions (FDIV, FEXP, FPI, etc.).

I believe you will have to write your own user programs using LongFloat functions . Since SolveSys is open source, you can read the source code and see how the program works. This does not sound like an easy undertaking to me though.

Also, since LongFloat is quite slow, I would expect such a user program to be very slow indeed.

John

Edit: another possibility is to use exact rational arithmetic, i.e. exact mode. This may not be suitable for your intended uses but exact integers tend to be significantly faster than LongFloats.

Hi John ... Well, I have tried some longfloat commands and it does not seem so slow, even with 25 decimal places it takes more or less 1 or 2 seconds to perform 5 calculations in a row. But what do you say about using exact arithmetic what does it mean? How can I do that with the HP 50g? And something else: according to the link I shared about that system of equations, how can such a system be solved on the HP 50g if its precision is 12 digits? It means that if that system or another similar one appears we would not be able to solve it with our calculator and we would have to resort to software like Mathematica?

Can something be done using System RPL and have the calculator do calculations with more decimals?