Print _Arccsc(x)

Print Atn(1 / Sqr(1 - x * x)) + (Sgn(x) - 1) * (2 * Atn(1))

(01-15-2024, 02:34 PM)dbox Wrote: In the process of trying to expand QBJS' support for QB64 keywords I noticed a curiosity with the extended trigonometric functions.  It looks like this has been the case for some time and predates "the incident".

There is a bit of inconsistency with the documentation in the wiki(s) for the support of these keywords.  Some are well documented and have their own page like: _acos, _asin, _hypot, etc..  Many of them, however, are only referenced in the "Derived Mathematical Functions" section of the Mathematical Operations page.  This section, though, is really just a reference of how to implement your own trig functions and doesn't really indicate that many (but not all) of those methods are actually available in the language.

The following functions from this section have first-class keyword support:
_sec, _csc, _cot, _arcsec, _arccsc, _arccot, _sinh, _cosh, _tanh, _sech, _csch, _coth

...while these do not have a dedicated keyword:
_arcsin, arccos, _arcsinh, _arccosh, _arccsch, _arccoth

So the curiosity that I found is related to the _arccsc method.  If you run the following example you will see that you get two different answers for built-in function vs the provided logic in the wiki:

Code: (Select All)

Print _Arccsc(x)

Print Atn(1 / Sqr(1 - x * x)) + (Sgn(x) - 1) * (2 * Atn(1))

Which one is right?

(01-15-2024, 02:49 PM)SMcNeill Wrote: And some of those where wrong, as discussed and patched here: https://qb64phoenix.com/forum/showthread.php?tid=2125

I don't know if the wiki was ever corrected, or not.  Someone will need to check that soon.  

(01-15-2024, 02:38 PM)SpriggsySpriggs Wrote: I wish I understood math well enough to actually use these functions.

(01-15-2024, 02:49 PM)SMcNeill Wrote: And some of those where wrong, as discussed and patched here: https://qb64phoenix.com/forum/showthread.php?tid=2125

I don't know if the wiki was ever corrected, or not.  Someone will need to check that soon.  

(01-15-2024, 04:56 PM)RhoSigma Wrote:

(01-15-2024, 02:49 PM)SMcNeill Wrote: And some of those where wrong, as discussed and patched here: https://qb64phoenix.com/forum/showthread.php?tid=2125

I don't know if the wiki was ever corrected, or not.  Someone will need to check that soon.  

Indeed, there are a  couple math keywords without a dedicated wiki page yet. Those should have been added by the one who actually implemented the keywords into the language and hence knows best how they work. However, I've no idea who was it, my best guess either of @luke, @FellippeHeitor or @SMcNeill.

_ARCCOT, _ARCCSC, _ARCSEC, _COT, _COTH, _COSH, _CSC, _CSCH, _SEC, _SECH, _SINH, _TANH

In alternative anybody who's familiar with this kind of math could take the task, just let me know if you need a wiki account. Wish my Dad would still be alive, as math teacher he could explan all this to the best, unfortunately I did not inherit much of his math talents 

(01-15-2024, 06:42 PM)bplus Wrote: @dbox to be a total nag, it seems to me a more productive use of time to get _Maptriangle working than exotic math functions.

The only people that would use exotic math functions can create their own from building blocks of the basic ones such as Sin, Cos and Tan and their Arc- prefixes because they would be quite familiar with and skilled at using Trig Indentities.