|Re: wp34s 2.0 Beta Release|
Message #30 Posted by Dieter on 10 June 2011, 10:24 a.m.,
in response to message #1 by Marcus von Cube, Germany
The first thing I noticed was a permanent decimal point/comma even for integers in ALL and FIX 0. This always annoyed me on other calculators. On the 41-series this can be solved by clearing Flag 29 (thousands separator off), while on the 34s even after E3OFF the decimal marker remains visible.
While we are on this topic: some time ago we had a discussion concerning an improved standard display format that switches to scientific notation only if the value is below 0,01 or 0,001. If memory serves well, this was generally considered a good idea. So, how about that?
I also wonder if there is a way that makes SHOW display all 16 digits. Yes, I know the display only has 12 digits. I also would prefer the classic MANT/SHOW style that also displays trailing zeroes. But the 16-digit issue is something I really would appreciate.
The second thing I tried was - once again ;-) - the precision of the statistical distributions and their inverses. The Chi-square quantile still returns values that are completely off. Try 10 d.o.f. and p = 1E-9 and you will get something like 2,01256 (which also looks like it required substantial execution time on a physical 20s/30s), while the correct result is 0,083152. In the meantime I have found a method that gives a nice initial estimate for the Chi-square quantile, which is within -10...+6% of the true value (or even +/-3% after some tweaks). In most cases a 16-digit result is obtained after 4 - 6 iterations. Also, an estimate for the F-quantile should be no big problem. Let me know if there's sufficient space left and the better estimate can be implemented.