[PEPr] Comment on Math::Math_AP

Etienne Kneuss (http://pear.php.net/user/colder) has commented on the proposal for Math::Math_AP. Comment: (I thought it would be better to make it a comment instead of a simple reply) Hello, After a quick look into the code, I would like to make some suggestions/remarks : 1) Where is my_pi() defined?? (used line 137) 2) There could be some improvements in the algorithms, like: - You should save the result of "bcpow($num, 2)" and using only multiplications instead of "bcpow($num,2 * $i + 1,$sc)" - The exp algorithm is highly divergent for negative input, you'll need some tricks( e^-x = 1/e^x and e4.8 = (((e^0.6)^2)^2) for example). - don't use "($i/2 != floor($i/2))" but ($i & 1) -> much faster - you should warn the user about invalid input: acos(), asin(), ln()... - the atan() taylor's developpement only works with input in the interval [-1;1], you'll need some tricks (trigonometric transformations) to allow a wider range. - some algorithms **need** at lot of loops to become relevant, I don't see the point using $scale as a brake condition, you should break the loop on a relative error basis. 3) I don't really like the way you get the Pi value, especially if its the only reason to have zlib in dependencies. There is also a way to calculate this value. 4) Applying P.C.S would make the code much more readable. 5) I can imagine unexpected results, because of the intermediary simplifications using $scale+<arbitrary number>. There's probably a better way to do it. Kind regards Proposal information: http://pear.php.net/pepr/pepr-proposal-show.php?id=340 -- Sent by PEPr, the automatic proposal system at http://pear.php.net