16 Point Gaussian Quadrature for the HP-41C/CV/CX (updated)

[Namir]

The four integration tests that you listed are very intgersting for testing HP-15C calculators and emulators. I used the integral of 1/sqrt(x) from 0 to 1. Here are some results!

HP-15 LE gave 1.9998705
HP-15C CE keeps running with NO solution!
JRPN 15C version 2.18 gave 1.9961232
RLM 15 emulator emulator gave 5.878602E44
HP15C emulator Version 4.5.00, Build 6308 © 1997-2023 Torsten Manz gave 1.9932975

I was very suprised that the HP-15C kept going. I stopped the calculator after a few minutes!

I believe that the HP-15C is using a version of Romberg integration. Is this true?

I usually test algorithms with easy cases to see if they work at all, and if my implementatipon is correct.

Namir