[WP-34S] Chi-Square Distribution

[Paul Dale]

(01-12-2014 02:37 PM)Dieter Wrote:  Maybe there's a problem with the initial guess. Could you provide the first guesses for df=20 and p = 1E-10, 0,05, 0,95 and 0,99999? Or is there a way to single-step through the routine so that I can do this myself? The initial guess should be within approx. ±10% of the final result.

It should be possible. Turning trace mode on lets you single step through xrom. I'm not sure how to do this in any emulator except the console one (which you really don't want to use These programs could be typed in in user mode, which often is the best way to debug them.

Yeah, the initial guess is bad for some input values:

Code:

 1E-10    0.9454441852127046    0.9057457376233529524406618674391
 .05    10.85081139418259    30.903880572067197129947058754473
 .95    31.41043284423093    30.903880572067197129947058754473
 .99999    59.04455038680165    57.7753881925718842706491638346524
 .9    28.41198058430563    28.0176453217379586052786281495866
 .4    16.26585648501278    19.343125586513683013556720398377658

Seems good for larger values and really small ones. Pretty bad at .05 however.

Time for some digging into code.


- Pauli