RE: [PEAR-DEV] New package proposal: Math_Calculus

--- Lukasz Karapuda <luke@thenewline.com> wrote: > Jesus, > > The site www.phpmath.com is still a BETA release, so don't expect to > find there too much stuff at the moment. I do agree that PEAR coding > standards, as well as phpDocumentor compatible inline documentation > should be used. However at this point it's difficult to enforce this, > because other admins are not exactly concerned with the format. Hmm, if you are going to have a big code base, you do need to agree on some coding standards, as the maintainance of the code is shared (I presume) among the developers, and not just each one has its own code separated from each others code. For your project to be an integrated one, you do need some rules of understanding/use, the PEAR ones as as good as any other. Also, you do not comment on using the pear installer infrastructure, or whether you (and I use the you in the sense of 'the phpmath.com developers') would like to contribute or publish your package(s) via PEAR, or even use/interface with the existing code in PEAR. What is your position on this respect? > The reason I got very interested in this particular project is because > one of the admins had already published 2 articles on IBM developerworks > about the Regression classes, present in the toolkit. I thought that > this would be a great incentive for PHP developers to get involved. > > Here are the articles: > http://www-106.ibm.com/developerworks/web/library/wa-linphp2/ > http://www-106.ibm.com/developerworks/web/library/wa-linphp/ Indeed, but as the saying goes 'code talks louder than 1,000 nice UML diagrams' (well there is no saying like that, but there should be one ;-), and the code for the linear regression seems good and solid, but it could use documentation. Bottomline, would the phpmath.com people use the infrastructure or packages from PEAR? And that is a two-way street, so if you got some nice code I can use on some package I maintain, I will be more than happy to require the appropriate package/class from the phpmath.com collection. Hope to get definitive answers on this respect. BTW, do you realize that the phpmath.com only renders correctly under Mozilla (I am using Solaris and Linux, not Windows or OSX)? It renders badly on Netscape 4.7x (yes I am still using that on Solaris), and Opera for Solaris. I think there is some problem with the javascript, on Netscape I get the error: JavaScript Error: http://www.phpmath.com/js/js_3.php, line 126: document.getElementById is not a function. On Opera 5.0b1 (Solaris) I do not get the navigation bar at the top. Cheers. > Regards, > __________________________________________ > Lukasz Karapuda [ lkarap00@mercyhurst.edu ] > Mercyhurst Web Developer > Y! lukaszkarapuda > > > -----Original Message----- > From: Jesus M. Castagnetto [mailto:jcastagnetto@yahoo.com] > Sent: Monday, May 19, 2003 6:39 PM > To: Lukasz Karapuda; 'Johannes Schlueter' > Cc: pear-dev@lists.php.net > Subject: RE: [PEAR-DEV] New package proposal: Math_Calculus > > Hi Lukasz and Johannes, > > > --- Lukasz Karapuda <luke@thenewline.com> wrote: > > > Overall the idea is good. The implementation needs some work. For > > example, > > > a stable and reliable differentiation package could be use to solve > > funding > > > the roots of an equations using any of the well-known methods (e.g. > > > Newton-Raphson's). > > > > If you are considering developing a reliable and complete > > differentiation package, take a look at �.s= > >
Q�: ~�a�http://www.phpmath.com. > > Sounds interesting. A more encompasing project than the 'Numeric PHP' > (one that > I started eons ago, and now have terminated). Most of the code from that > is in > PEAR now (see the Math_* packages). > > > It's a > > major effort to create a complete mathematical toolkit for PHP > (language > > based). > > Went to the site, found not much information. In particular I was > expecting to > see some downloadable code. I found the autocorrelation, distribution, > and > linear regression stuff code (some of which can be factored out to other > packages, eg. Math_Stats in PEAR). > > > I am one of the administrators, and currently we are looking at > > as many contributors as possible. Perhaps you could join our mailing > > list. We currently have implemented Simple Linear Regression, Matrix > > Operations and Linear Algebra. > > I did not see any matrix operations code (see PEAR::Math_Matrix). Also, > it > would be a good idea to use the PEAR Code Standards, for both the actual > PHP > code and the code documentation. Also, you might consider creating a > package.xml so the classes can be installed using the PEAR installer. > Finally, why not consider to create a series of Math_* classes that can > be > included/integrated in PEAR. Having a team of maintainers that can be > grouped > under the phpmath.com site would be great, that way the code will be > better and > the errors/bugs fewer. This can be done in two ways, by adding the > packages as > they are approved to PEAR's CVS, or by keeping the code in a separate > CVS and > releasing them via PEAR, or both ;-) > > > > > Best Regards, > > > > __________________________________________ > > Lukasz Karapuda [ lkarap00@mercyhurst.edu ] > > Mercyhurst Web Developer > > Y! lukaszkarapuda > > > > > > -----Original Message----- > > From: Johannes Schlueter [mailto:phpng@schlueters.de] > > Sent: Saturday, May 17, 2003 10:03 AM > > To: Jesus M. Castagnetto > > Cc: pear-dev@lists.php.net > > Subject: Re: [PEAR-DEV] New package proposal: Math_Calculus > > > > On Friday 16 May 2003 23:45, you wrote: > > > The class looks OK for simple functions withouth many singular > points. > > > As it stands now, I would not recommend its inclusion in PEAR: -1 > > > > Ok. > > > > > 1) The name of the class: Perhaps you will be better of having 2 or > > more > > > Math_Numerical_Differentiation, Math_Numerical_Integration, etc. Or > > how > > > about a Math_Numerical (or Math_NumericalMethod or > > Math_NumericalSolution?) > > > class that works as facade to the ones implementing the algorithms? > > > > Math_Numerical looks good, but then we need many method's with it, but > > I'll > > look how I can implement all useful Numerical Alogrithms with PHP ;-) > > > > > > > 2) The implementation of your differentiation function, if you are > > handed a > > > non-continuous function, then you will be in trouble using the > simple > > > approach, w/o previously testing for continuity in the interval > where > > you > > > > Yes, that's true. The version I posted was the work of very few hours, > > just > > for solving a problem I had. Therefore it worked. Then I saw there's > no > > such > > thing for PEAR so I wrote some comments to see the reactions, imho it > > don't > > make sense spending hours of work if nobody wants it ;-) > > > > > are calculating the derivative. A look at: > > > http://lib-www.lanl.gov/numerical/index.html, and in > > > particular at: > > > http://lib-www.lanl.gov/numerical/bookfpdf/f5-7.pdf, > > > will surely > help > > in > > > this respect. Might also need to be careful not to generate an > > floating > > > point overflow. > > > > The links look really interesting. All have a closer look over these > an > > improve my code. > > > > > 3) The implementation of the Romberg's integration method tries to > > minimize > > > errors by using iterations of the trapezoidal rule. But for > analytical > > > functions, you might be better using other approaches. > > > > Romberg'smethod was the one I've found most implementations for and > the > > one > > I've understood easily ;-) > > > > > 4) The method that finds point of a function where the derivative is > > zero > > > is OK, but it is of no use if it is not coupled with one that find > the > > > extrema (minima and maxima). Also, if might be better named > > > findZeroDerivative() instead. Of course you will need to define a > > second > > > derivative method for the extrema. > > > > Yes... > > > > > Overall the idea is good. The implementation needs some work. For > > example, > > > a stable and reliable differentiation package could be use to solve > > funding > > > the roots of an equations using any of the well-known methods (e.g. > > > Newton-Raphson's). > > > > > > The URL mentioned above has a lot of great numerical recipes. And as > > we > > > cannot add GSL to PECL due to licensing conflicts, perhaps > > implementing > > > them in PHP would be nice. > > > > If I'm going to implement all of them I'll never be bored again. And > if > > I'm > > still bored I can implement it using BCMath, GMP and PEAR > Math_Complex. > > ;-) > > > > johannes > > > > > ===== > --- Jesus M. Castagnetto (jcastagnetto@yahoo.com) > > Research: > http://metallo.scripps.edu/ > Personal: http://www.castagnetto.org/ > > __________________________________ > Do you Yahoo!? > The New Yahoo! Search - Faster. Easier. Bingo. > http://search.yahoo.com > ===== --- Jesus M. Castagnetto (jcastagnetto@yahoo.com) Research: http://metallo.scripps.edu/ Personal: http://www.castagnetto.org/ __________________________________ Do you Yahoo!? The New Yahoo! Search - Faster. Easier. Bingo. http://search.yahoo.com