[Libreoffice] [REVIEW] fix for fdo#37218: tinv only takes values up to 10000 as second parameter

[Regina Henschel]

Hi Markus,

Markus Mohrhard schrieb:
> Hello,
>
> this patch removes the check for the upper bound of the second parameter
> of TINV. I checked the algorithm of TINV but there seems to be no reason
> to limit this number.
>
> The only problem is that for values greater than 1E14 the rounding error
> dramatically increases but in my opinion everyone who uses such large
> numbers should know about problems related to rounding and floating
> point arithmetic.

I have no definite opinion on the upper limit of the second parameter. 
It is "degree of freedom" and 1E5 covers already exploring 5000 records. 
I don't know whether a larger limit is needed. But the user should get 
an information about problems with huge numbers, perhaps a remark in the 
help, that it is not recommended to use values above ...

Do you have valid reference values for the accuracy? Are the values of 
TINV worse or better than approximating with standard normal distribution?

There are some loops involved. Do you test the performance with huge values?

Kind regards
Regina