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

[Namir]

(11-12-2023 03:24 PM)Valentin Albillo Wrote:  

(11-12-2023 08:38 AM)Namir Wrote:  Example 1 0.6931471810
Example 2 0.9313784470

Both values end in 0 ? Really ? It's a 1-in-100 chance. Did you multiply them by 10 as I suggested ? If yes, then they'd be like 6.93... and 9.31... respectively, not the 0.693... and 0.931... values you posted.
Could you please check them out one final time ?

Thanks and regards.
V.

Yes I multiplied both results by 10 ans then moved the decimal to the right, so they correspond to the original answers (now with 10 digits)..

Using MATLAB, I calculated log(2) (the integral of 1/x from 1 to 2) and got 0.693147180559945. Comparing this result with what I got on the HP-41CX, looks like the 41CX rounded the part of 8055 into 810. I assume the calculator might have done similar rounding to the result of Example 2.