newRPL - build 1255 released! [updated to 1299]

[Claudio L.]

(12-21-2019 02:52 PM)_nmr_ Wrote:  About PROOT.
Symmetric vectors hangs calculator.
[ 1 2 3 4 5 4 3 2 1] needs longer time to evaluate roots.
[1 2 3 4 5 6 5 4 3 2 1] hangs up the calculator.
[1 2 3 4 5 6 7 6 5 4 3 2 1] hangs up the calculator.

I fixed this issue, it will come up on the next update.
Turns out the problem was with root multiplicity (which happens on all those symmetric coeff. vectors), the small rounding errors were not detecting multiplicity properly. I now require the result of the polynomial to be zero with a precision of 7/8 of the current system precision. In other words, for 32 digits I allow errors of up to 32/8 = last 4 digits. Before I was allowing for rounding error on the last digit only, and this was not enough for higher degree polynomials.
Once the algorithm missed a multiple root it would loop forever...